Infinite menu question?

I am using Kirupa’s Infinite menu. It is working great except I am using it on an elastic site and the center point always changes. Any idea on how I can get the center point to always stay in the middle of the screen when the screen resolution is resized.

here is the code:

onClipEvent (load)
   xcenter= Stage.width/2;
onClipEvent (enterFrame)
   var distance=_root._xmouse-xcenter;
   if (_x > 0) _x=-2226;
   if (_x < -2226) _x=0;

any idea of what i should put for


Thanks in advance!