Bug fix for approval chain manage to allow selection of null values.

application/modules/requests/controllers/ApprovalChainManagerController.php

@@ -102,13 +102,22 @@ class Requests_ApprovalChainManagerController extends App_Controller_Action
         foreach ($links as $link) {
             if ($in['currentAction'][$link->getId()] != '_null') {
                 $link->setCurrentActionId($in['currentAction'][$link->getId()]);
+            } else {
+            	$link->setCurrentActionId(NULL);
             }
+            
             if ($in['currentState'][$link->getId()] != '_null') {
                 $link->setCurrentState($in['currentState'][$link->getId()]);
+            } else {
+                $link->setCurrentState(NULL);
             }
+            
             if ($in['nextAction'][$link->getId()] != '_null') {
                 $link->setNextActionId($in['nextAction'][$link->getId()]);
+            } else {
+                $link->setNextActionId(NULL);
             }
+            
             if ($in['delete'][$link->getId()]) {
                 $linksToDelete[] = $link;
             } else {