Listen for a variable change?

1

i’m trying to determine whether the value of a certain variable has changed…

basically the code is something like this:


this.onEnterFrame = function() {
 if (loaded != filesize) {
  _root.preloader._visible = true;
  _root.preloader.preloader_text.text = Math.round(loaded/filesize*100);
 } else if (loaded=filesize) {
  _root.laius = _root.picture._width;
  _root.korgus = _root.picture._height;
  _root.preloader._visible = false;
 }
}

i need to figure out how to determine when values of _root.laius and _root.korgus change…

any ideas ?