How can I ignore an error using Events with a TCL eval step - I get "Unable to evaluate "set servicepack [query Portal_Response2 Service_Pack($phone)]" : Invalid query : Incorrect number of arguments" when $phone is NULL.
The events are just like a try catch block execution, so the scenario is we can ignore the error messgae if we are aware of the error or warning events (agree to Yaseen). When you see this message, the "servicepack" variable NOT set at all as the statemet NOT being executed. So the better situation is if you execute the statement only when $phone is NOT NULL or $phone exists (as per your situation).
For we don't have any event you could use info exists command before using your logic e.g. info exists servicePack For more information on info command
http://www2.tcl.tk/1185 I hope this could help you.