How to make frames or screen sizes?

I need to design a page that relies heavily on percentage of current frame size. I tried making this with tables, but the result was not near as good as with the good old frames. So my question is, how can I easily add support for frames? I need to have three frames/columns one for menu top bar, and one for content and one for left filler. I don't see how I can do this with just tables. Any suggestions? SOmetimes I wish I was back in html/asp coding again :) Then I didn't have to bother with gridlayouts :)


Oh, a second question: How do I use a "save as" form? I have a button on my webpage that saves a file, but I need some kind of GUI where the user can select dest + filename., I know how to do this in java, but how is it done in asp.net?


kind regards
HEnrik