I'm trying to figure out how to have an iframe with constant scrollbars so the scrollbars are visible even though there is nothing to scroll!

I have this now:
Code:
<script type="text/javascript">
function ChangeScrollState (select) {
	var iframe = document.getElementById ("thisIframe");
	var frameDoc = iframe.contentWindow.document;
	frameDoc.documentElement.style.overflow = select.value;
}
</script>

<iframe id="thisIframe" src="testpage.php" /></iframe>

<select onChange="ChangeScrollState (this);" size="3">
    <option value="auto"  />auto
    <option value="scroll" selected="selected" />show
    <option value="hidden" />hide
</select>
If I hit the option with scroll I get what I want, but how do I make this static?

Hoping for help :-)