Index: trunk/FACT++/scripts/Observation_class.js
===================================================================
--- trunk/FACT++/scripts/Observation_class.js	(revision 14767)
+++ trunk/FACT++/scripts/Observation_class.js	(revision 14768)
@@ -74,4 +74,8 @@
                     "if 'task' == 'ratescan'");
             }
+            break;
+        default:
+            throw new Error(" the task of this observation:"+this.task+ 
+                            "is not implemented. use one of: DATA, STARTUP, SHUTDOWN, RATESCAN.");
     }