How to detect whether scrollbar is showing up in Netscape?

[bin_bin1]

Hello, all, In my current project, I need to display a control at the upper-right corner of the browser window. But when the vertical scrollbar is showing up in Netscape, that control will be displayed over the scrollbar, which is not desirable. I'd like to know whether there is a way to detect whether the vertical scrollbar is showing up or not, so that I can move the control a little bit when scrollbar is displayed. I searched all day online and tried all kinds of method to do it, but none of them works. I am using javascript in the current project. Thanks a lot in advance. Bin