1) Keep first frame clean to add loading to first frame.

2) create load_mc movieclip on first frame with 100 frame of loading animation. and a dynamic textbox inside load_mc named percent_txt;

3) give an instance name to load_mc - "load_mc"
4) finally add the following script to first frame of your flash document.
----------------------------------------------------------------------------------
stop();
var timer:Timer=new Timer(10);
timer.addEventListener(TimerEvent.TIMER,loading);
timer.start();
function loading(evt:Event)
{
var loaded=root.loaderInfo.bytesLoaded;
var total=root.loaderInfo.bytesTotal;
var percent=Math.ceil((loaded/total)*100);
load_mc.percent_txt.text=percent+"%";
load_mc.gotoAndStop(percent);
if(loaded>=total)
{
timer.stop();
gotoAndStop(2);
}
}
-----------------------------------------------------------------------------------
download FLA file
