How can i get Screen's Width&Height Of Mobile

There have been some issues with obtaining the accurate screen width and height at startup, and what some of us have done is to implement code which waits a  few seconds before grabbing that info. Something along these lines(you'll have to work this code into your own app):

private var _appHeight;

private var _appwidth;

private var _startup_delay;

//set delay for app startup

_startup_delay = 10;

//add listener for enter frame

addEventListener(Event.ENTER_FRAME, _handleEnterFrame);  

private function _handleEnterFrame(e:Event):void{

         //start at 10 and count down to zero.

         _startup_delay--;

            //start the delay

            if(_startup_delay <= 0){

                //remove enter frame listener

                removeEventListener(Event.ENTER_FRAME, _handleEnterFrame);

               //configure the stage--------------------------------------------------------//

                stage.scaleMode = StageScaleMode.NO_SCALE;

                stage.align = StageAlign.TOP_LEFT;

                stage.quality = "high";

              //grab screen width and height

               _appwidth = stage.stageWidth;

               _appHeight = stage.stageHeight;

            }

        }