Index: /trunk/FACT++/scripts/CheckUnderflow.js
===================================================================
--- /trunk/FACT++/scripts/CheckUnderflow.js	(revision 20097)
+++ /trunk/FACT++/scripts/CheckUnderflow.js	(revision 20098)
@@ -125,9 +125,10 @@
     while (1)
     {
+	var endloop=false;
         var event_counter = service_event.get(10000, false).counter;
 
         var stop = function ()
         {
-            while (1)
+            while(!endloop) 
             {
                 if (dim.state("MCP").name=="TakingData" && service_event.get(0, false).counter>event_counter)
@@ -145,5 +146,5 @@
         var rc = takeRun("drs-gain");
 
-        thread.kill();
+        endloop=true;
 
         if (rc)