Modal Popup Offset in website with Master Page

Hi.

I am using the Atlas modal popup tool in my website. However, the popup covers only the ContentPlaceHolder tag area and the other parts of the Master Page, namely the header and the leftcolumn (where I have menu options) are not covered. Curiously, the alpha filter seems to be offset by the area of the header and the leftcolumn. This really has me stumped. Any help would be deeply appreciated.

I am using tables to align my controls, but removing the Panel that is displayed as the modal popup from the table and placing it below the table seems to have no affect.

Thanks!

I think you'll findthis thread helpful.
Thanks for the link. It was helpful and I was able to sort my problem. The problem was that one of the div tags that wraps around all my content had the position set to "relative". A very basic error I guess, but I am a beginner after all!! Thanks again for the reply and link.