Does anyone know how to do it?

This is what I have so far:

 window.onload = windowLoad; 
function windowLoad() {
 xAddEventListener(xGetElementById('sidebar'), "resize", resizeLayout, false);
function resizeLayout() {
 sidebar_h  = xHeight("sidebar");
 contents_h = xHeight("contents");
 if (sidebar_h < contents_h) {
  xHeight("sidebar", contents_h);
 } else {
  xHeight("contents", sidebar_h);
I'm using the X library. But, the resize event is never fired.

I want to do this because my 2 column layout is incorrectly resized when the user changes the font size of his browser. The columns' height get unsynched again.

Thanks in advance!