private var fileReferenceLoad:FileReference = new FileReference();
 
private function onLoadImage():void
{
    var f:FileFilter = new FileFilter("Images", "*.jpg;*.gif;*.png;*.jpeg");
    fileReferenceLoad.browse([f]);
    fileReferenceLoad.addEventListener(Event.SELECT,onFileSelect);
    fileReferenceLoad.addEventListener(Event.COMPLETE,onFileComplete);
}
private function onFileSelect(event:Event):void
{
    fileReferenceLoad.load();
}
 
private function onFileComplete(event:Event):void
{
     var byteArray:ByteArray = fileReferenceLoad.data;
     //
 }