Run-Time Errors cause wierdness

Question

I have a remote object call that sends a query string to a
database. I am trying to catch errors coming from the database
because of bad sql statements. In my code there is an IF statements
that checks if the first row returned is an object by trying to
convert it to a string. If it is not equal to "[object Object]"
then I know its an error message generated from the database. My
problem is as soon as I uncomment the IF statement and test my app
everything begins acting wierd as soon as my app hits that logic.
Items highlight, tree controls show junk, etc. If I comment out the
IF everything works fine but I get a alert for rows returned and
one with the error message. I tried enclosing everything in a try
catch but there seems to be no run-time error occuring. Has anybody
else experience wierd things when errors occur?
private function queryResults(event:ResultEvent):void
var call:Object = event.token;
var isError:Boolean = false;
if( call.state == "FillGrid" )
results = event.result as ArrayCollection;
if( results.length == 1 )
var errMsg:String = results.getItemAt(0).toString();
//if( errMsg != "[object Object]" )
Alert.show(errMsg,"Error");
//isError = true;
if( !isError)
results.filterFunction = searchData;
Alert.show( results.length.toString() + " Rows Returned!
","Results");
SortColumns();
if( results.length > 0 )
calculateGrandTotals(results);

Answer 1

I have adjusted some of the logic in my code and now it works
fine. I would still like to know what was causing the wierd stuff.
private function queryResults(event:ResultEvent):void
var call:Object = event.token;
var isError:Boolean = false;
var msg:String = "";
var msgHeader:String = "Results";
if( call.state == "FillGrid" )
var tmpResults:ArrayCollection = event.result as
ArrayCollection;
msg = tmpResults.length.toString() + " Rows Returned! ";
if( tmpResults.length == 1 )
var errMsg:String = tmpResults.getItemAt(0).toString();
if( errMsg != "[object Object]" )
msg = errMsg;
msgHeader = "Error";
isError = true;
Alert.show( msg,msgHeader);
if( isError == false )
results = tmpResults;
results.filterFunction = searchData;
SortColumns();
if( results.length > 0 )
calculateGrandTotals(results);
}