ReportViewer and dynamic size with IE7 problem

[Chris Botha]

This problem originated months ago when I wanted the ReportViewer control to
take up most of the current size of the IE window, even if the user sizes
the IE window.
So as a kick-off I made the height 80% and the width 90% in the designer,
however when the report loaded, the height did not stay 80%, it became
small - the width stayed 90% though.
So then I used Java script to size the height of the ReportViewer control
dynamically when the page loads in IE and this works fine for IE6, however
since installing IE7, the script does not work, the height is small. Here
follows the script - it comes right at the bottom of the page:

<script type="text/javascript" language="javascript">
var theViewer = document.getElementById("ReportViewer1");
theViewer.style.height = "80%";
</script>

The script still finds the right HTML element - if I do a:
alert(theViewer.style.height);
before I set it to 80%, it shows the correct height assigned in the
designer.

NOTE that if I use pixels in the script, example "600px" then the script
sizes it, but 80% is what I want - to stay 80% even if the user sizes the IE
window.

So if anyone knows how to get the script working, or any other method to get
the height 80%, it will be appreciated.