The question is very simple: how do I render an FBX/3DS model in WebGL? I've tried googling around, but this seems like a pretty new area.
As i've replied to you on another question, currently there are lots of problems that arise when you try to use WebGL. Chunked 3D formats that aren't UTF-8 "decodable" (text) can't be consistently loaded without browser trickery with buffers (which aren't neither standard nor API/stable). In this case, you should implement your own 3DS loader on Javascript and make it run on both Firefox and Chrome (although the buffers trick isn't useful on chrome AFAIK).
Your best bet is to use a text format like OBJ or ASE. I myself have begun work on a JSON exporter for blender here that works nicely with WebGL, but of course, it is only useful if you're using Blender 2.5+.