Web servise response problem

Question

Hello all. I use  webservise in my web applicatiuon(Flex 3).I request to web servise and  receive  result with successully.
But sometimes I cannot result of web servise,because I receive this error messages.
1.Response cannot be decoded Raw responce/
2.RangeError Index '0' specified is out of bounds/
code example
<mx:WebService id="srv1" wsdl="http://localhost:8080/Report_/get_report_typesService?WSDL" endpointURI="http://localhost:8080/Report_/get_report_typesService" fault="defaultFault(event)">
     <mx:operation name="get_reports" resultFormat="xml"    result="get_input_data(event)" />
     </mx:WebService>   
srv1.get_reports.send(parseInt(text_pasword.text));
var get_xml_reports:XML=new XML(evt.result);
     xmlListColl = new XMLListCollection(get_xml_reports.children()._report_name);             

Answer 1

I tried surround try{}catch{}. servise is running and I receive.But still sometimes servise is not responsed and I still  same error mesages
1.Response cannot be decoded Raw responce/
2.RangeError Index  '0' specified is out of bounds/