When "Frames" first arrived on the scene, there was a mad scramble to feature this "cutting edge" feature on websites across the net. Till designers started realising that people don´t like them!

Frames divide your browser screen into independent areas. You can scroll one frame without affecting other areas of the screen. Sounds like a great idea, except that site visitors get confused.  Add to this the fact that you can´t print out more than one frame at a time (so your printout will feature - for instance - only the skinny left-hand frame, while you wanted the MAIN frame...), and the fact that browsers tend to display frames rather erratically... honestly,  there isn´t a lot going for them.  (Go to http://websitesthatsuck.com/suckframe.htm for some examples of how frames work, or try http://www.useit.com/alertbox/9612.html for a summary of the difficulties that they create).

Nothing dates your site quite as surely as using jaded technology, so our advice is to avoid frames like the plague, in favour of the "shared borders", which FP2000 (not to mention every other reputable web-authoring tool) supports.