diff --git a/openslides/assignment/models.py b/openslides/assignment/models.py
index 650d517d1..5579e5ea8 100644
--- a/openslides/assignment/models.py
+++ b/openslides/assignment/models.py
@@ -18,22 +18,31 @@ from django.utils.datastructures import SortedDict
 from openslides.utils.person import PersonField
 from openslides.utils.utils import html_strong
 from openslides.config.api import config
-from openslides.projector.models import SlideMixin
+from openslides.projector.models import SlideMixin, RelatedModelMixin
 from openslides.poll.models import (
     BasePoll, CountInvalid, CountVotesCast, BaseOption, PublishPollMixin, BaseVote)
 
 
-class AssignmentCandidate(models.Model):
+class AssignmentCandidate(RelatedModelMixin, models.Model):
+    """
+    Many2Many table between an assignment and the candidates.
+    """
     assignment = models.ForeignKey("Assignment")
     person = PersonField(db_index=True)
     elected = models.BooleanField(default=False)
     blocked = models.BooleanField(default=False)
 
+    class Meta:
+        unique_together = ("assignment", "person")
+
     def __unicode__(self):
         return unicode(self.person)
 
-    class Meta:
-        unique_together = ("assignment", "person")
+    def get_related_model(self):
+        """
+        Returns the assignment
+        """
+        return self.assignment
 
 
 class Assignment(SlideMixin, models.Model):
@@ -74,6 +83,12 @@ class Assignment(SlideMixin, models.Model):
             return reverse('assignment_delete', args=[str(self.id)])
         return super(Assignment, self).get_absolute_url(link)
 
+    def get_slide_context(self, **context):
+        context.update({
+            'polls': self.poll_set.filter(published=True),
+            'vote_results': self.vote_results(only_published=True)})
+        return super(Assignment, self).get_slide_context(**context)
+
     def set_status(self, status):
         status_dict = dict(self.STATUS)
         if status not in status_dict:
@@ -241,15 +256,29 @@ class AssignmentOption(BaseOption):
         return unicode(self.candidate)
 
 
-class AssignmentPoll(BasePoll, CountInvalid, CountVotesCast, PublishPollMixin):
+class AssignmentPoll(RelatedModelMixin, CountInvalid, CountVotesCast,
+                     PublishPollMixin, BasePoll):
     option_class = AssignmentOption
 
     assignment = models.ForeignKey(Assignment, related_name='poll_set')
     yesnoabstain = models.NullBooleanField()
 
+    def __unicode__(self):
+        return _("Ballot %d") % self.get_ballot()
+
+    @models.permalink
+    def get_absolute_url(self, link='detail'):
+        if link == 'view' or link == 'detail' or link == 'update':
+            return ('assignment_poll_view', [str(self.pk)])
+        if link == 'delete':
+            return ('assignment_poll_delete', [str(self.pk)])
+
     def get_assignment(self):
         return self.assignment
 
+    def get_related_model(self):
+        return self.assignment
+
     def get_vote_values(self):
         if self.yesnoabstain is None:
             if config['assignment_poll_vote_values'] == 'votes':
@@ -274,13 +303,3 @@ class AssignmentPoll(BasePoll, CountInvalid, CountVotesCast, PublishPollMixin):
 
     def get_ballot(self):
         return self.assignment.poll_set.filter(id__lte=self.id).count()
-
-    @models.permalink
-    def get_absolute_url(self, link='detail'):
-        if link == 'view' or link == 'detail' or link == 'update':
-            return ('assignment_poll_view', [str(self.id)])
-        if link == 'delete':
-            return ('assignment_poll_delete', [str(self.id)])
-
-    def __unicode__(self):
-        return _("Ballot %d") % self.get_ballot()
diff --git a/openslides/assignment/slides.py b/openslides/assignment/slides.py
index dee057a82..744fac9f6 100644
--- a/openslides/assignment/slides.py
+++ b/openslides/assignment/slides.py
@@ -10,29 +10,8 @@
     :license: GNU GPL, see LICENSE for more details.
 """
 
-from django.template.loader import render_to_string
-
-from openslides.config.api import config
-from openslides.projector.api import register_slide
+from openslides.projector.api import register_slide_model
 from .models import Assignment
 
 
-def assignment_slide(**kwargs):
-    """
-    Slide for an Assignment
-    """
-    assignment_pk = kwargs.get('pk', None)
-    try:
-        assignment = Assignment.objects.get(pk=assignment_pk)
-    except Assignment.DoesNotExist:
-        return ''
-
-    polls = assignment.poll_set
-    context = {
-        'polls': polls.filter(published=True),
-        'vote_results': assignment.vote_results(only_published=True),
-        'assignment': assignment}
-
-    return render_to_string('assignment/slide.html', context)
-
-register_slide(Assignment.slide_callback_name, assignment_slide)
+register_slide_model(Assignment, 'assignment/slide.html')
diff --git a/openslides/assignment/templates/assignment/assignment_detail.html b/openslides/assignment/templates/assignment/assignment_detail.html
index bba20fbaa..53daa97e5 100644
--- a/openslides/assignment/templates/assignment/assignment_detail.html
+++ b/openslides/assignment/templates/assignment/assignment_detail.html
@@ -179,7 +179,7 @@
             {% endfor %}
             {% if assignment.candidates and perms.assignment.can_manage_assignment and assignment.status == "vot" %}
                 <th class="span1 nobr">
-                    <a href="{% url 'assignment_poll_create' assignment.id %}" class="btn btn-mini">
+                    <a href="{% url 'assignment_poll_create' assignment.pk %}" class="btn btn-mini">
                        <i class="icon-plus"></i> {% trans 'New ballot' %}
                     </a>
                 </th>
diff --git a/openslides/assignment/urls.py b/openslides/assignment/urls.py
index fcc7dc16b..5fec7c4ce 100644
--- a/openslides/assignment/urls.py
+++ b/openslides/assignment/urls.py
@@ -99,6 +99,8 @@ urlpatterns = patterns('openslides.assignment.views',
         name='assignment_poll_delete',
     ),
 
+    # TODO: use seperate urls to publish and unpublish the poll
+    #       see assignment_user_elected
     url(r'^poll/(?P<pk>\d+)/pub/$',
         SetPublishStatusView.as_view(),
         name='assignment_poll_publish_status',
diff --git a/openslides/assignment/views.py b/openslides/assignment/views.py
index eb44c59e1..822c996ac 100644
--- a/openslides/assignment/views.py
+++ b/openslides/assignment/views.py
@@ -246,10 +246,10 @@ class PollUpdateView(PollFormView):
 class SetPublishStatusView(SingleObjectMixin, RedirectView):
     model = AssignmentPoll
     permission_required = 'assignment.can_manage_assignment'
-    url_name = 'assignment_list'
+    url_name = 'assignment_detail'
     allow_ajax = True
 
-    def get_ajax_context(self):
+    def get_ajax_context(self, **kwargs):
         return {'published': self.object.published}
 
     def pre_redirect(self, *args, **kwargs):
@@ -258,15 +258,11 @@ class SetPublishStatusView(SingleObjectMixin, RedirectView):
         except self.model.DoesNotExist:
             messages.error(self.request, _('Ballot ID %d does not exist.') %
                            int(kwargs['poll_id']))
-            return
-        if self.object.published:
-            self.object.set_published(False)
         else:
-            self.object.set_published(True)
-        if self.object.published:
-            messages.success(self.request, _("Ballot successfully published."))
-        else:
-            messages.success(self.request, _("Ballot successfully unpublished."))
+            if self.object.published:
+                self.object.set_published(False)
+            else:
+                self.object.set_published(True)
 
 
 class SetElectedView(SingleObjectMixin, RedirectView):
@@ -281,14 +277,14 @@ class SetElectedView(SingleObjectMixin, RedirectView):
         self.elected = kwargs['elected']
         self.object.set_elected(self.person, self.elected)
 
-    def get_ajax_context(self):
+    def get_ajax_context(self, **kwargs):
         if self.elected:
             link = reverse('assignment_user_not_elected',
                            args=[self.object.id, self.person.person_id])
             text = _('not elected')
         else:
             link = reverse('assignment_user_elected',
-                           args=[self.self.object.id, self.person.person_id])
+                           args=[self.object.id, self.person.person_id])
             text = _('elected')
         return {'elected': self.elected, 'link': link, 'text': text}
 
diff --git a/openslides/motion/models.py b/openslides/motion/models.py
index 053b43c49..bb204c1d5 100644
--- a/openslides/motion/models.py
+++ b/openslides/motion/models.py
@@ -23,14 +23,15 @@ from django.utils import formats
 from django.utils.translation import pgettext
 from django.utils.translation import ugettext as _, ugettext_lazy, ugettext_noop
 
-from openslides.utils.jsonfield import JSONField
-from openslides.utils.person import PersonField
+from openslides.agenda.models import Item
 from openslides.config.api import config
+from openslides.participant.models import User
 from openslides.poll.models import (
     BaseOption, BasePoll, CountVotesCast, CountInvalid, BaseVote)
-from openslides.participant.models import User
-from openslides.projector.models import SlideMixin
-from openslides.agenda.models import Item
+from openslides.projector.models import SlideMixin, RelatedModelMixin
+from openslides.projector.api import (update_projector, get_active_slide)
+from openslides.utils.jsonfield import JSONField
+from openslides.utils.person import PersonField
 
 from .exceptions import MotionError, WorkflowError
 
@@ -584,7 +585,7 @@ class MotionVersion(models.Model):
         return self.active_version.exists()
 
 
-class MotionSubmitter(models.Model):
+class MotionSubmitter(RelatedModelMixin, models.Model):
     """Save the submitter of a Motion."""
 
     motion = models.ForeignKey('Motion', related_name="submitter")
@@ -597,6 +598,9 @@ class MotionSubmitter(models.Model):
         """Return the name of the submitter as string."""
         return unicode(self.person)
 
+    def get_related_model(self):
+        return self.motion
+
 
 class MotionSupporter(models.Model):
     """Save the submitter of a Motion."""
@@ -695,7 +699,7 @@ class MotionOption(BaseOption):
     """The VoteClass, to witch this Class links."""
 
 
-class MotionPoll(CountInvalid, CountVotesCast, BasePoll):
+class MotionPoll(RelatedModelMixin, CountInvalid, CountVotesCast, BasePoll):
     """The Class to saves the poll results for a motion poll."""
 
     motion = models.ForeignKey(Motion, related_name='polls')
@@ -722,7 +726,8 @@ class MotionPoll(CountInvalid, CountVotesCast, BasePoll):
         return _('Vote %d') % self.poll_number
 
     def get_absolute_url(self, link='edit'):
-        """Return an URL for the poll.
+        """
+        Return an URL for the poll.
 
         The keyargument 'link' can be 'edit' or 'delete'.
         """
@@ -744,9 +749,13 @@ class MotionPoll(CountInvalid, CountVotesCast, BasePoll):
         CountInvalid.append_pollform_fields(self, fields)
         CountVotesCast.append_pollform_fields(self, fields)
 
+    def get_related_model(self):
+        return self.motion
+
 
 class State(models.Model):
-    """Defines a state for a motion.
+    """
+    Defines a state for a motion.
 
     Every state belongs to a workflow. All states of a workflow are linked together
     via 'next_states'. One of these states is the first state, but this
diff --git a/openslides/motion/slides.py b/openslides/motion/slides.py
index 13b05c9a0..17ff5ca03 100644
--- a/openslides/motion/slides.py
+++ b/openslides/motion/slides.py
@@ -10,26 +10,7 @@
     :license: GNU GPL, see LICENSE for more details.
 """
 
-from django.template.loader import render_to_string
-
-from openslides.projector.api import register_slide
+from openslides.projector.api import register_slide_model
 from .models import Motion
 
-
-def motion_slide(**kwargs):
-    """
-    Slide for the motion app.
-    """
-    motion_pk = kwargs.get('pk', None)
-    try:
-        motion = Motion.objects.get(pk=motion_pk)
-    except Motion.DoesNotExist:
-        return ''
-
-    context = {
-        'motion': motion,
-        'title': motion.title}
-
-    return render_to_string('motion/slide.html', context)
-
-register_slide(Motion.slide_callback_name, motion_slide)
+register_slide_model(Motion, 'motion/slide.html')
diff --git a/openslides/motion/views.py b/openslides/motion/views.py
index 260445d37..82bdf5156 100644
--- a/openslides/motion/views.py
+++ b/openslides/motion/views.py
@@ -11,36 +11,36 @@
     :copyright: (c) 2011–2013 by the OpenSlides team, see AUTHORS.
     :license: GNU GPL, see LICENSE for more details.
 """
+from reportlab.platypus import SimpleDocTemplate
 
 from django.core.urlresolvers import reverse
 from django.contrib import messages
 from django.db import transaction
 from django.db.models import Model
+from django.http import Http404, HttpResponseRedirect
 from django.utils.text import slugify
 from django.utils.translation import ugettext as _, ugettext_lazy, ugettext_noop
-from django.http import Http404, HttpResponseRedirect
-
-from reportlab.platypus import SimpleDocTemplate
 
+from openslides.agenda.views import (
+    CreateRelatedAgendaItemView as _CreateRelatedAgendaItemView)
+from openslides.config.api import config
+from openslides.poll.views import PollFormView
+from openslides.projector.api import get_active_slide, update_projector
+from openslides.projector.projector import Widget
 from openslides.utils.pdf import stylesheet
+from openslides.utils.template import Tab
+from openslides.utils.utils import html_strong, htmldiff
 from openslides.utils.views import (
     TemplateView, RedirectView, UpdateView, CreateView, DeleteView, PDFView,
     DetailView, ListView, FormView, QuestionMixin, SingleObjectMixin)
-from openslides.utils.template import Tab
-from openslides.utils.utils import html_strong, htmldiff
-from openslides.poll.views import PollFormView
-from openslides.projector.api import get_active_slide
-from openslides.projector.projector import Widget
-from openslides.config.api import config
-from openslides.agenda.views import CreateRelatedAgendaItemView as _CreateRelatedAgendaItemView
 
-from .models import (Motion, MotionSubmitter, MotionSupporter, MotionPoll,
-                     MotionVersion, State, WorkflowError, Category)
+from .csv_import import import_motions
 from .forms import (BaseMotionForm, MotionSubmitterMixin, MotionSupporterMixin,
                     MotionDisableVersioningMixin, MotionCategoryMixin,
                     MotionIdentifierMixin, MotionWorkflowMixin, MotionImportForm)
+from .models import (Motion, MotionSubmitter, MotionSupporter, MotionPoll,
+                     MotionVersion, State, WorkflowError, Category)
 from .pdf import motions_to_pdf, motion_to_pdf, motion_poll_to_pdf
-from .csv_import import import_motions
 
 
 class MotionListView(ListView):
@@ -127,6 +127,15 @@ class MotionEditMixin(object):
             MotionSupporter.objects.bulk_create(
                 [MotionSupporter(motion=self.object, person=person)
                  for person in form.cleaned_data['supporter']])
+
+        # Update the projector if the motion is on it. This can not be done in
+        # the model, because bulk_create does not call the save method.
+        active_slide = get_active_slide()
+        active_slide_pk = active_slide.get('pk', None)
+        if (active_slide['callback'] == 'motion' and
+                unicode(self.object.pk) == unicode(active_slide_pk)):
+            update_projector()
+
         messages.success(self.request, self.get_success_message())
         return HttpResponseRedirect(self.get_success_url())
 
diff --git a/openslides/participant/models.py b/openslides/participant/models.py
index 931f0f5ca..31f7f11c2 100644
--- a/openslides/participant/models.py
+++ b/openslides/participant/models.py
@@ -80,6 +80,11 @@ class User(SlideMixin, PersonMixin, Person, DjangoUser):
             return reverse('user_delete', args=[str(self.id)])
         return super(User, self).get_absolute_url(link)
 
+    def get_slide_context(self, **context):
+        # Does not call super. In this case the context would override the name
+        # 'user'.
+        return {'shown_user': self}
+
     @property
     def clean_name(self):
         if self.title:
diff --git a/openslides/participant/slides.py b/openslides/participant/slides.py
index 58ff0f91b..62a529ff1 100644
--- a/openslides/participant/slides.py
+++ b/openslides/participant/slides.py
@@ -10,39 +10,8 @@
     :license: GNU GPL, see LICENSE for more details.
 """
 
-from django.template.loader import render_to_string
-
-from openslides.projector.api import register_slide
+from openslides.projector.api import register_slide_model
 from .models import User, Group
 
-
-def user_slide(**kwargs):
-    """
-    Slide for the user model.
-    """
-    user_pk = kwargs.get('pk', None)
-    try:
-        user = User.objects.get(pk=user_pk)
-    except User.DoesNotExist:
-        return ''
-
-    context = {'shown_user': user}
-    return render_to_string('participant/user_slide.html', context)
-
-register_slide(User.slide_callback_name, user_slide)
-
-
-def group_slide(**kwargs):
-    """
-    Slide for the group model.
-    """
-    group_pk = kwargs.get('pk', None)
-    try:
-        group = Group.objects.get(pk=group_pk)
-    except Group.DoesNotExist:
-        return ''
-
-    context = {'group': group}
-    return render_to_string('participant/group_slide.html', context)
-
-register_slide(Group.slide_callback_name, group_slide)
+register_slide_model(User, 'participant/user_slide.html')
+register_slide_model(Group, 'participant/group_slide.html')
diff --git a/openslides/projector/api.py b/openslides/projector/api.py
index a0937a54f..91f07b593 100644
--- a/openslides/projector/api.py
+++ b/openslides/projector/api.py
@@ -40,18 +40,17 @@ def update_projector():
 
 def update_projector_overlay(overlay):
     """
-    Update one overlay on the projector.
+    Update one or all overlay on the projector.
 
     Checks if the overlay is activated and updates it in this case.
 
-    'overlay' has to be an overlay object, the name of a ovleray or None.
-
-    If 'overlay' is None, then all overlays are updated.
+    The argument 'overlay' has to be an overlay object, the name of a
+    ovleray or None. If it is None, all overlays will be updated.
     """
-    if isinstance(overlay, basestring):
-        overlay = get_overlays()[overlay]
     if overlay is None:
         overlays = [overlay for overlay in get_overlays().values()]
+    elif isinstance(overlay, basestring):
+        overlays = [get_overlays()[overlay]]
     else:
         overlays = [overlay]
 
@@ -132,6 +131,33 @@ def register_slide(name, callback):
     slide_callback[name] = callback
 
 
+def register_slide_model(SlideModel, template):
+    """
+    Shortcut for register_slide for a Model with the SlideMixin.
+
+    The Argument 'SlideModel' has to be a Django-Model-Class, which is a subclass
+    of SlideMixin. Template has to be a string to the path of a template.
+    """
+
+    def model_slide(**kwargs):
+        """
+        Return the html code for the model slide.
+        """
+        slide_pk = kwargs.get('pk', None)
+
+        try:
+            slide = SlideModel.objects.get(pk=slide_pk)
+        except SlideModel.DoesNotExist:
+            slide = None
+            context = {'slide': None}
+        else:
+            context = slide.get_slide_context()
+
+        return render_to_string(template, context)
+
+    register_slide(SlideModel.slide_callback_name, model_slide)
+
+
 def set_active_slide(callback, kwargs={}):
     """
     Set the active Slide.
@@ -147,7 +173,7 @@ def set_active_slide(callback, kwargs={}):
 
 def get_active_slide():
     """
-    Returns the dictonary, witch defindes the active slide.
+    Returns the dictonary, which defines the active slide.
     """
     return config['projector_active_slide']
 
diff --git a/openslides/projector/models.py b/openslides/projector/models.py
index 57d2a110f..eafd4b9d9 100644
--- a/openslides/projector/models.py
+++ b/openslides/projector/models.py
@@ -19,6 +19,39 @@ from django.core.urlresolvers import reverse
 from openslides.utils.utils import int_or_none
 
 
+class RelatedModelMixin(object):
+    """
+    Mixin for motion related models, that appear on the motion slide.
+    """
+
+    def save(self, *args, **kwargs):
+        """
+        Saves the model and updates the projector, if the motion in on it.
+        """
+        from .api import update_projector
+        value = super(RelatedModelMixin, self).save(*args, **kwargs)
+        if self.get_related_model().is_active_slide():
+            update_projector()
+        return value
+
+    def delete(self, *args, **kwargs):
+        """
+        Deletes the model and updates the projector, if the motion in on it.
+        """
+        from .api import update_projector
+        value = super(RelatedModelMixin, self).delete(*args, **kwargs)
+        if self.get_related_model().is_active_slide():
+            update_projector()
+        return value
+
+    def get_related_model(self):
+        """
+        Return the pk of the related model.
+        """
+        raise ImproperlyConfigured(
+            '%s has to have a method "get_related_model_pk"' % type(self))
+
+
 class SlideMixin(object):
     """
     A Mixin for a Django-Model, for making the model a slide.
@@ -34,42 +67,32 @@ class SlideMixin(object):
         Updates the projector, if 'self' is the active slide.
         """
         from openslides.projector.api import update_projector
-        super(SlideMixin, self).save(*args, **kwargs)
+        value = super(SlideMixin, self).save(*args, **kwargs)
         if self.is_active_slide():
             update_projector()
+        return value
 
     def delete(self, *args, **kwargs):
         from openslides.projector.api import update_projector
-        super(SlideMixin, self).delete(*args, **kwargs)
+        value = super(SlideMixin, self).delete(*args, **kwargs)
         if self.is_active_slide():
             update_projector()
-
-    def get_slide_callback_name(self):
-        """
-        Returns the name of the slide callback, which is used to render the slide.
-        """
-        if self.slide_callback_name is None:
-            raise ImproperlyConfigured(
-                "SlideMixin requires either a definition of 'slide_callback_name'"
-                " or an implementation of 'get_slide_callback_name()'")
-        else:
-            return self.slide_callback_name
+        return value
 
     def get_absolute_url(self, link='projector'):
         """
-        Return the url to activate the slide, if link == 'projector'
+        Return the url to activate the slide, if link == 'projector'.
         """
-        if link == 'projector':
-            url_name = 'projector_activate_slide'
-        elif link == 'projector_preview':
-            url_name = 'projector_preview'
-
         if link in ('projector', 'projector_preview'):
-            return '%s?pk=%d' % (
+            url_name = {'projector': 'projector_activate_slide',
+                        'projector_preview': 'projector_preview'}[link]
+            value = '%s?pk=%d' % (
                 reverse(url_name,
-                        args=[self.get_slide_callback_name()]),
+                        args=[self.slide_callback_name]),
                 self.pk)
-        return super(SlideMixin, self).get_absolute_url(link)
+        else:
+            value = super(SlideMixin, self).get_absolute_url(link)
+        return value
 
     def is_active_slide(self):
         """
@@ -78,15 +101,24 @@ class SlideMixin(object):
         from openslides.projector.api import get_active_slide
         active_slide = get_active_slide()
         pk = int_or_none(active_slide.get('pk', None))
-
-        return (active_slide['callback'] == self.get_slide_callback_name() and
+        return (active_slide['callback'] == self.slide_callback_name and
                 self.pk == pk)
 
+    def get_slide_context(self, **context):
+        """
+        Returns the context for the template which renders the slide.
+        """
+        slide_name = self._meta.object_name.lower()
+        context.update({'slide': self,
+                        slide_name: self})
+        return context
+
 
 class ProjectorSlide(SlideMixin, models.Model):
     """
     Model for Slides, only for the projector. Also called custom slides.
     """
+    # TODO: Rename it to CustomSlide
     slide_callback_name = 'projector_slide'
 
     title = models.CharField(max_length=256, verbose_name=ugettext_lazy("Title"))
diff --git a/openslides/projector/projector.py b/openslides/projector/projector.py
index ede8e3f7e..92daea2d0 100644
--- a/openslides/projector/projector.py
+++ b/openslides/projector/projector.py
@@ -102,7 +102,7 @@ class Overlay(object):
 
     def set_active(self, active):
         """
-        Publish or depublish the ovleray on the projector.
+        Publish or depublish the overlay on the projector.
 
         publish, if active is true,
         depublish, if active is false.
diff --git a/openslides/projector/slides.py b/openslides/projector/slides.py
index 6ecd7901e..cb20e3b0e 100644
--- a/openslides/projector/slides.py
+++ b/openslides/projector/slides.py
@@ -10,27 +10,9 @@
     :license: GNU GPL, see LICENSE for more details.
 """
 
-from django.template.loader import render_to_string
-
-from openslides.config.api import config
-from openslides.projector.api import register_slide
+from openslides.projector.api import register_slide_model
 
 from .models import ProjectorSlide
 
 
-def projector_slide(**kwargs):
-    """
-    Return the html code for a custom slide.
-    """
-    slide_pk = kwargs.get('pk', None)
-
-    try:
-        slide = ProjectorSlide.objects.get(pk=slide_pk)
-    except ProjectorSlide.DoesNotExist:
-        slide = None
-
-    context = {'slide': slide}
-    return render_to_string('projector/slide_projectorslide.html', context)
-
-
-register_slide('projector_slide', projector_slide)
+register_slide_model(ProjectorSlide, 'projector/slide_projectorslide.html')
diff --git a/openslides/utils/tornado_webserver.py b/openslides/utils/tornado_webserver.py
index f626ef474..a6a7219c6 100644
--- a/openslides/utils/tornado_webserver.py
+++ b/openslides/utils/tornado_webserver.py
@@ -39,8 +39,14 @@ class DjangoStaticFileHandler(StaticFileHandler):
 
 
 class ProjectorSocketHandler(WebSocketHandler):
+    """
+    Handels the websocket for the projector.
+    """
     waiters = set()
 
+    # The following lines can be uncommented, if there are any problems with
+    # websockts in iOS Safari 5.0
+
     ## def allow_draft76(self):
         ## # for iOS 5.0 Safari
         ## return True