Center a frameset

Hello everyone:

I need to center a frameset. Our web page is optimyed for 800x600 screen size. For higher resolutions, we center the page by using a table. Now, however, we need to use a frameset with a top-navbar and two frames below (looks like one part of a tennis court).

Currently I use an additional frame at the left with a blank page to center the whole stuff. This works fine wit Netscape where I can read the window width and with IE as long as the window equals the whole screen.

Is there either a way to center framesets or is there a way to get the siye of a browser window with IE?

Any help would be appreciated.

Thanks,

Dirk