Why not try normal frames ? But that's just my thought. IFrames are notoriously known to be exploited by some Trojans/Viruses / whatever.
With DHTML everything could look much better ... but that's a bit more difficult to program, I think (never used it so far, but must admit that I didn't program HTML pages in the last few years).
When you find a big kettle of crazy, it's best not to stir it. --Dilbert cartoon
"Interplay.some zombiefied unlife thing going on there" - skavenhorde at RPGWatch