Dnyamically Rewriting A Div Height

I'm trying to rewrite the height of a div to make it fit within an area of the
browser window. It works great in FireFox (no error/etc messages at
all). But in IE I receive an error. Here is the Javascript code I'm
trying to run:

<script type="text/javascript">
<!--
function equalize() {
var e = document.getElementById("left_column");
var newheight = window.innerHeight - 60;
e.style.height = newheight + 'px'
}
window.onresize=equalize;
//-->
</script>

I've tried changing my doctype header and all sorts of things (some of
my research led me to believe that might be my problem). The error I'm
receiving is:

Line: 261
Char: 2
Error: Invalid Argument
Code: 0

Line 261 is the line "e.style.height = newheight + 'px'"