diff --git a/kole.html b/kole.html
index 31dc57c..5fa2769 100644
--- a/kole.html
+++ b/kole.html
@@ -62,41 +62,51 @@
 <fieldset>
 	<legend></legend>
 	<section class="radiogroup">
-		<legend>Eingangsgröße</legend>
-		<input accesskey="b" type="radio" name="b" value="e" id="bb" class="bb" checked="checked"/><label for="bb"><u>B</u>rutto</label><input accesskey="n" type="radio" name="b" value="b" id="bn" class="bb"/><label for="bn"><u>N</u>etto</label><input accesskey="k" type="radio" name="b" value="k" id="bk" class="bb"/><label for="bk"><u>K</u>oLe</label>
+		<legend>Eingangsgröße</legend><!--
+		--><input accesskey="b" type="radio" name="b" value="e" id="bb" class="bb" checked="checked"/>&nbsp;<label for="bb"><u>B</u>rutto</label><!--
+		--><input accesskey="n" type="radio" name="b" value="b" id="bn" class="bb"/>&nbsp;<label for="bn"><u>N</u>etto</label><!--
+		--><input accesskey="k" type="radio" name="b" value="k" id="bk" class="bb"/>&nbsp;<label for="bk"><u>K</u>oLe</label>
 	</section>
 	<section>
 		<div>
-		<label for="e">Br<u>u</u>tto</label>
-		<input accesskey="u" type="number" step="0.01" id="e" value="100.00"/>&thinsp;€
+			<label for="e">Br<u>u</u>tto</label>
+			<input accesskey="u" type="number" step="0.01" id="e" value="100.00"/>&thinsp;€
 		</div>
 		<div>
-		<label for="u">Umsatzsteuersatz</label>
-		<input type="number" step="0.01" id="u" value="19.00"/>&thinsp;%
+			<label for="u">Umsatzsteuersatz</label>
+			<input type="number" step="0.01" id="u" value="19.00"/>&thinsp;%
 		</div>
 		<div>
-		<label for="us">Umsatzsteuer</label>
-		<input readonly="readonly" type="number" step="0.01" id="us" value="0.00"/>&thinsp;€
+			<label for="us">Umsatzsteuer</label>
+			<input readonly="readonly" type="number" step="0.01" id="us" value="0.00"/>&thinsp;€
 		</div>
 		<div>
-		<label for="n">N<u>e</u>tto</label>
-		<input accesskey="e" type="number" step="0.01" id="n" value="0.00"/>&thinsp;€
+			<label for="n">N<u>e</u>tto</label>
+			<input accesskey="e" type="number" step="0.01" id="n" value="0.00"/>&thinsp;€
 		</div>
 		<div>
-		<label for="z">Entropieumlagesatz</label>
-		<input type="number" step="0.01" id="z" value="23.00"/>&thinsp;%
+			<label for="ec">Entropie-Tarif</label><!-- ggf. künftig Grundlage wie Handbuch/Dokumentation verlinken -->
+			<select id="ec">
+				<option value="l" accesskey="l" name="low">Umsatz &leq; 1.000&nbsp;€</option><!-- low: <=1 TEUR -->
+				<option value="h" accesskey="h" name="high">Umsatz &gt; 1.000&nbsp;€</option><!-- high: >1 TEUR -->
+				<option value="c" accesskey="c" name="custom">nach&nbsp;Vereinbarung</option><!-- custom: separate agreement -->
+			</select>
 		</div>
 		<div>
-		<label for="eu">Entropieumlage</label>
-		<input readonly="readonly" type="number" step="0.01" id="eu" value="23.00"/>&thinsp;€
+			<label for="z">Entropieumlagesatz</label>
+			<input type="number" step="0.01" id="z" value="23.00"/>&thinsp;%
 		</div>
 		<div>
-		<label for="k">K<u>o</u>Le</label>
-		<input accesskey="o" type="number" step="0.01" id="k" value="0.00"/>&thinsp;€
+			<label for="eu">Entropieumlage</label>
+			<input readonly="readonly" type="number" step="0.01" id="eu" value="23.00"/>&thinsp;€
+		</div>
+		<div>
+			<label for="k">K<u>o</u>Le</label>
+			<input accesskey="o" type="number" step="0.01" id="k" value="0.00"/>&thinsp;€
 		</div>
 	</section>
 	<section>
-		<button accesskey="c" id="b" type="button">Bere<u>c</u>hnen</button>
+		<button accesskey="r" id="b" type="button">Be<u>r</u>echnen</button>
 	</section>
 
 </fieldset>
@@ -109,10 +119,11 @@
 		var z=document.getElementById('z');
 		var eu=document.getElementById('eu');
 		var k=document.getElementById('k');
-		var bb=document.getElementById('bb'); 
-		var bn=document.getElementById('bn'); 
-		var bk=document.getElementById('bk'); 
+		var bb=document.getElementById('bb');
+		var bn=document.getElementById('bn');
+		var bk=document.getElementById('bk');
 		var s = document.getElementById('b');
+		var c = document.getElementById('ec');
 
 		function getFormFloat(f){
 			return parseFloat(f.value);
@@ -122,6 +133,8 @@
 		}
 
 		s.addEventListener('click', function(){
+			c.selectedIndex=0;
+			z.disabled=true;
 			if(bk.checked){
 				e.value = roundCents( getFormFloat(k) * ( 1 + getFormFloat(u) / 100 ) / ( 1 - getFormFloat(z) / 100 ) );
 				n.value = roundCents( getFormFloat(k) / ( 1 - getFormFloat(z) / 100 ) );
@@ -137,6 +150,26 @@
 		});
 		e.addEventListener('change', function(){bb.checked = true;});
 		n.addEventListener('change', function(){bn.checked = true;});
+		c.addEventListener('change', function(){
+			var selInd=this.selectedIndex;
+			console.log('Entropie-Tarif: '+selInd+'('+z.disabled+': '+z.value+')');
+			switch(selInd){
+				case 0: //low: <1.000 EUR revenue
+					//23.0 %
+					z.value='23.00';
+					z.disabled=true;
+					break;;
+				case 1: //high: >1.000 EUR revenue
+					//11.5 %
+					z.disabled=true;
+					z.value='11.50';
+					break;;
+				case 2: //custom: according toseparate agreement
+					z.disabled=false;
+					//~ z.focus();
+					break;;
+			}
+		});
 		s.click();
 	</script>
 	</div>