scrollWidth mystery

[Guest]

hey all,
i have the following DIV element in my page:

<DIV id="OnlyDIV" style="OVERFLOW: hidden; WIDTH: 300px">...

This div element contains a datalist. This works fine for me on a regular
webform in that it gives me the correct scrollWidth value. The problem is
when i place this code inside my master page the scrollWidth value then
becomes 0. And i have no idea why. i've debugged it and right from the start
it has a value of 0.

x=document.getElementById("OnlyDIV");
right after this statement
x.scrollWidth is 0

and the only difference is it's in a master page. any ideas?

thanks,
rodchar