MIME Types

I'm writing an upload application in ASP and would like to restrict file uploads to TEX and LaTex files. I'm finding that for TEX files created using Scientific Word/Workplace, the recognized MIME type for such files is application-octet stream. Since this is the same as for executables, it's not much use in restricting the kind of files that can be uploaded. Has anyone else run into this kind of problem? Any suggestions on how to proceed so that the people I work with can upload TEX produced by SW?

Thanks in advance for any help.