POST with multipart/form-data using libwww

Hi,
       I need one urgent help. I am using HTPostAnchor(src, dst, request) 
thrugh C.  I have set 
HTAnchor_setFormat(src,HTAtom_for("multipart/form-data")),
      Can you please give me piece of code what is boundary? how do i set 
it?

            I can see in mailing list :
                                                        
HTAnchor_addFormatParam(src,"boundary",boundary);------>what should 
boundary contain?
Can someone give me piece of code?

Thanks


Regards,
Shailendra Desai