loadVariables to LoadVars

Okay, so ive loaded some data from PHP into a textbox in Flash with loadVariables, but then found out, that loadVariables, havent got a way of checking if everythings loaded. So im gonna use LoadVars instead, i just need some help with the code. This is the old loadVariables code:

on(rollOver){
   loadVariables("document.php", _parent, "POST");
   bgheight = _root.textbox._height+((_root.textbox._y-_root.tester._y)*2);
   maskheight = _root.textbox._height+((_root.textbox._y-_root.tester._y)*2);
   _root.tester.scale(bgheight);
   _root.tester2.scale(maskheight);}

This way it works fine, except that it does the height setting, before content is actually loaded into the textbox. How should this code look with LoadVars to work?