Optional Subs to Avi films

[Treasurer]

I've been searching for eternity and I still haven'tfound what I'm looking for.

I want to add optional subs to my Avi files, but It seems so complicated.

I have a standalone DVD/DivX player which support .srt and .sub files. I've learned how to add permanent subs via VobSub and VDub, but the Optional subs are really tricky any help would be great!

Any guides?

[Treasurer]

Well I've found out how to use SubMux now, so I'm only writing this to help others that might have the same problem.
SubMux cannot work with avi files that have a VBR MP3 audio stream. So if SubMux only make a small kb file, then it's because of the audio stream. But Don't worry, just remove the audio stream in VirtualDub.
Video -> Direct stream copy, and Audio -> No sound. many guides, just google it. Hope this is any help for people with same problem, and for those who want a Permanent Subtitle guide, go to:

http://divxstation.com/article.asp?aId=100

Excellent guide!