prevent the scroll bars to show up

[umen]

Hello
i have page that has onLoad="window.resizeTo(120, 120)" in the body , i have in the body hidden "<div>"
<div id="blah" style="position:absolute; display:none; width:150px;" ></div>

now i show the div whit simple script something like :
blah.style.display='block';

but when the div is shows up i get the width and height scrollers
not to show up? and i dont mean to prevent the scrolling to all the page but only to this div.

thanks.
p.s
it can be css question im not sure