How to Get / Set Div and Table Width / Height - asp.net

Question

I have a Table (or a region) and want to set it's Width and Height value to another Div (or region).
The second one is actually a Ajax Indicator modal which display a loading text when the page is asynchronously post back. here is the example
<table id="MainTable">
<tr>
<td>
Content ....
</td>
</tr>
</table>
<div id="Progress">
Ajax Indocator
</div>
the following javascript didn't work
document.getElementById("Progress").style.width = document.getElementById("MainTable").style.width;
document.getElementById("Progress").style.height = document.getElementById("MainTable").style.height;
It should work both on IE and FireFox. how to correct it.
I checked some other solution in StackOverFlow but I couldn't fix it.
I'm waiting to hear from you.
Update : I use this
<script>
function SetSize(regionToChange, mainRegion) {
$(document).ready(function() {
$('#regionToChange)
.width($('#mainRegion).outerWidth())
.height($('#mainRegion).outerHeight());
});
}
</script>
and I call it like
<asp:Button ID="btnReset" runat="server" SkinID="Button" Text="Reset" OnClick="btnReset_OnClick" OnClientClick="SetSize('Progress', 'MainTable');" />
But it shows me an error which can not find the object
Update 2 I see this error
and in debugger I face with this

Answer 1

spoken in jQuery:
$(document).ready(function(){
$('#Progress')
.width($('#MainTable').outerWidth())
.height($('#MainTable').outerHeight());
});

Answer 2

in jQuery you can do
$("#Progress").css('width', function(){
return $("#MainTable").width()+'px';
});
and so with the height...
edit
on javascript,
this
document.getElementById("Progress").style.width = document.getElementById("MainTable").style.width;
document.getElementById("Progress").style.height = document.getElementById("MainTable").style.height;
will work if your html is something like this for id="MainTable"
<table id="MainTable" style="width: 500px; height: 300px;">
<tr>
<td>
Content ....
</td>
</tr>
</table>
because you are accessing style attribute...
edit2
function SetSize(regionToChange, mainRegion) {
$(regionToChange)
.width($(mainRegion).outerWidth())
.height($(mainRegion).outerHeight());
}
//you can use it as
SetSize('#Progress','#MainTable'); // prefix '#'if it's an ID