DOM Updated Question

I have a site with a 3 column layout. Because the size of the columns may be different onLoad, I am using Javascript to make each of the columns the same height. This works great when I load the page.

However, my site updates these columns using AJAX. After the update, one column may have become longer than the others. I am trying to find a way to detect this change and then again make all 3 columns the same height.

My first approach was with an event handler that detected "onsubtreemodified" for these DIVs. Unfortunately, this is a fairly new W3C DOM event that is not currently supported by most browsers.

My next idea was to simply call the function that did the resize with the onClick event when the user did anything that would update the columns. This does not work because Javascript does not wait until the DOM is finished updating before executing the code that checks sizes. So, it still sees the columns as the same height and doesn't make adjustments.