How to call Webservice from flex

<![CDATA[
import mx.rpc.events.FaultEvent;
import mx.managers.CursorManager;
import flash.trace.Trace;
import mx.controls.Alert;
import mx.rpc.events.ResultEvent;
import mx.rpc.soap.WebService;

private function callSOAP():void{
var service:WebService = new WebService();
service.wsdl = "http://localhost:8080/webproject/services/UserLogin?wsdl";
service.getUserdetails.addEventListener("result",userDetailsResultfunction);
service.loadWSDL();
service.getUserdetails("argument1","argument2");
}
private function userDetailsResultfunction(event:ResultEvent):void{
var xmlResult:XML;
xmlResult = XML(event.result);
Alert.show("Result : " + xmlResult.toString());
}
]]>