use the FileReference.onProgress event listener
ActionScript 2.0 Language Reference
ActionScript classes >
FileReference (flash.net.FileReference) >
onProgress
example -
PHP Code:
var fileRef:FileReference = new FileReference();
var listener:Object = new Object ();
listener.onProgress =
function(file:FileReference, bytesLoaded:Number, bytesTotal:Number):Void{
var PC:Number = Math.round(bytesLoaded/bytesTotal*100);
var TL:Number = Math.round((bytesTotal/1024));
loadbar.txt.text = "Transferring: " +PC+"% of " +TL+" Kbs";
loadbar.gotoAndStop(PC);
};
fileRef.addListener(listener);