diff --git a/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/OPListController.java b/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/OPListController.java
index aee22c3..c55b6f2 100644
--- a/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/OPListController.java
+++ b/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/OPListController.java
@@ -114,21 +114,23 @@ public class OPListController implements Serializable {
             } catch (QueryException e) {
                 logger.severe("Failed to get op liste:" + e.getMessage());
             }
-            // wir selektieren hier alle fälligen Rechnungen vor, falls der Mahnlauf gerade erstellt
+            // wir selektieren hier alle fälligen Rechnungen vor, falls der Mahnlauf gerade
+            // erstellt
             // wird.
-            if (workflowController.getWorkitem().getItemValueInteger("$version") == 0
-                    || (workflowController.getWorkitem().getItemValueInteger("$version") == 1
-                            && workflowController.getWorkitem().getItemValueInteger("$lastevent") == 100)) {
-                List<String> intialSelection = new ArrayList<String>();
-                for (ItemCollection invoice : invoiceList) {
-                   
-                    if ("workitem".equals(invoice.getType()) && invoice.getTaskID()>=5100) {
-                        intialSelection.add(invoice.getUniqueID());
-                    }
-                }
-                workflowController.getWorkitem().setItemValue("$workitemref", intialSelection);
-            }
+            if (workflowController.getWorkitem().getModelVersion().startsWith("mahnlauf")) {
+                if (workflowController.getWorkitem().getItemValueInteger("$version") == 0
+                        || (workflowController.getWorkitem().getItemValueInteger("$version") == 1
+                                && workflowController.getWorkitem().getItemValueInteger("$lastevent") == 100)) {
+                    List<String> intialSelection = new ArrayList<String>();
+                    for (ItemCollection invoice : invoiceList) {
 
+                        if ("workitem".equals(invoice.getType()) && invoice.getTaskID() >= 5100) {
+                            intialSelection.add(invoice.getUniqueID());
+                        }
+                    }
+                    workflowController.getWorkitem().setItemValue("$workitemref", intialSelection);
+                }
+            }
         } else {
             // We are no longer in TASK_ERSTELLUNG, so
             // fetch only selected invoices
@@ -286,14 +288,32 @@ public class OPListController implements Serializable {
      */
     public double calculateInvoiceSaldo() {
         double result = 0;
-        for (ItemCollection invoice : invoiceList) {
-            result = result + invoice.getItemValueDouble("invoice.saldo");
+        if (invoiceList != null) {
+            for (ItemCollection invoice : invoiceList) {
+                result = result + invoice.getItemValueDouble("invoice.saldo");
+            }
         }
         // rond with 2 digits
         return Math.round(result * 100.0) / 100.0;
 
     }
 
+    /**
+     * Berechnet den noch offenen Differenz vom Zahlbetrag
+     * 
+     * @return
+     */
+    public double calculatePaymentDifference() {
+        double paymentAmount = workflowController.getWorkitem().getItemValueDouble("payment.amount");
+        double paymentTotal =  workflowController.getWorkitem().getItemValueDouble("payment.total");
+        // paymentAmount - calculateInvoiceSaldo();
+        double result = paymentAmount -paymentTotal;
+
+        logger.info("...new PaymentDifference=" + result);
+        // rond with 2 digits
+        return Math.round(result * 100.0) / 100.0;
+    }
+
     /**
      * Returns true if the reminder date is today or in the past
      * 
diff --git a/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste.xhtml b/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste.xhtml
index 5798169..26cc0ba 100644
--- a/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste.xhtml
+++ b/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste.xhtml
@@ -16,6 +16,17 @@
 	<h:panelGroup layout="block" styleClass="imixs-form-section"
 		id="oplist-table" binding="#{opListContainer}">
 
+
+		<dl>
+			<dt>Restbetrag:</dt>
+			<dd style="color:red;" data-item='payment.difference'>
+				<h:outputText value="#{opListController.calculatePaymentDifference()}">
+					<f:convertNumber minFractionDigits="2" locale="de" />
+				</h:outputText>
+			</dd>	
+		</dl>
+	
+
 		<table style="width: 100%; margin: 5px;">
 			<tr>
 				<th style="text-align: left;">#{message['form.invoicenumber']}</th>
@@ -88,7 +99,7 @@
 							value="#{invoice.item['payment.amount']}"
 							style="width:100px;text-align: right;">
 							<f:convertNumber minFractionDigits="2" locale="de" />
-							<f:ajax event="change" execute="#{opListContainer.clientId}"
+							<f:ajax event="change" execute="#{formComponents.clientId} #{opListContainer.clientId}"
 								listener="#{opListController.updateChildList(workitem)}"
 								render="#{opListContainer.clientId}"></f:ajax>
 						</h:inputText>
@@ -105,7 +116,7 @@
 					<td><h:selectBooleanCheckbox class="invoice_selector" rendered="#{!readonly}"
 							value="#{invoice.item['selected']}"
 							onclick="initInvoicePayment(this)">
-							<f:ajax event="change" execute="#{opListContainer.clientId}"
+							<f:ajax event="change" execute="#{formComponents.clientId} #{opListContainer.clientId}"
 								listener="#{opListController.updateChildList(workitem)}"
 								render="#{opListContainer.clientId}"></f:ajax>
 						</h:selectBooleanCheckbox></td>
@@ -154,12 +165,18 @@
 		/*<![CDATA[*/
 		$(document).ready(
 			function() {
-				// update the checkboxes of the stored invoice uniqueIDs
-			//	updateInvoiceSelection();
+				// default payment date
+				var inputPaymentDate=$("input[data-item='payment.date']");
+			    if (inputPaymentDate && inputPaymentDate.val()==='') {
+			    	const d = new Date();
+			    	const text = d.getDate()+'.'+(d.getMonth()+1) + '.'+d.getFullYear();// d.toString();
+			    	inputPaymentDate.val(text);
+     			}
 			});
 		
 		
 		    // set the payment amount to the invoice total if the field is still empty
+		    // if the paymetn dif is lower than the invoice saldo we take the dif amount
 			function initInvoicePayment(element) {
 				console.log('...initInovicePayment...'+element.checked);
 				
@@ -168,9 +185,21 @@
 				var amountValue=$(prevTD).text();
 				var amountTD=$(currentTD).prev();
 				var amountInput=$("input",amountTD);
-				// wenn wir noch keinen wert dann betrag übernehmen
+				var maxAmount=$("dd[data-item='payment.difference']").text();
+				maxAmount = maxAmount.replace(/\t/g, '');
+				maxAmount = maxAmount.replace('\n', '');
 				
+				v1=amountValue.replace(".","");
+				v1=Number(v1.replace(",","."));
+				
+				v2=maxAmount.replace(".","");
+				v2=Number(v2.replace(",","."));
+				
+				if (v1>v2) {
+					amountValue=maxAmount;
+				}
 				if (element.checked) {
+					// wenn wir noch keinen wert haben, dann betrag übernehmen
 					if ($(amountInput).val()=='' || $(amountInput).val()=='0,00') {
 						$(amountInput).val(amountValue);
 					}
diff --git a/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste_mahnlauf.xhtml b/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste_mahnlauf.xhtml
index 392a8d0..09c7a6b 100644
--- a/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste_mahnlauf.xhtml
+++ b/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/alexander/section_opliste_mahnlauf.xhtml
@@ -97,10 +97,10 @@
 			</ui:repeat>
 
 			<tr style="border-top: 1px solid #ccc;">
-				<td />
+				<td /><td />
 				<td /><td />	
 				<td><strong>Summary</strong></td>
-
+ 
 				<!-- Invoice total -->
 				<td style="text-align: right;"><strong> <h:panelGroup
 							id="invoice_total">
diff --git a/workflow/zahlungseingang-de-1.0.0.bpmn b/workflow/zahlungseingang-de-1.0.0.bpmn
index c758ab6..bcd1959 100644
--- a/workflow/zahlungseingang-de-1.0.0.bpmn
+++ b/workflow/zahlungseingang-de-1.0.0.bpmn
@@ -390,7 +390,7 @@ result.isValid=true;
     <item name="payment.date" type="date"  required="true"   label="Datum:" />
   </imixs-form-section>
   <imixs-form-section>
-    <item name="name" type="text"  required="true"   label="Referenz:" />
+    <item name="name" type="text"  required="false"   label="Referenz:" />
 
   </imixs-form-section>
   <imixs-form-section columns="2" >
@@ -480,7 +480,7 @@ result.isValid=true;
       <bpmn2:documentation id="Documentation_16"><![CDATA[<?xml version="1.0"?>
 <imixs-form>
   <imixs-form-section columns="2" label="Zahlungsdaten">
-    <item name="name" type="text"  required="true"   label="Referenz:" />
+    <item name="name" type="text"  required="false"   label="Referenz:" />
     <item name="dbtr.number" type="text"  required="true"   label="Debitor:" />
     <item name="payment.amount" type="currency"  required="true"   label="Zahlbetrag:" />
     <item name="payment.currency" type="selectOneMenu" required="true" options="EUR;CHF;SEK;RUB;NOK;GBP;USD;CAD"   label="Währung:" />