> why dll file is not working in vb6.0. it is not being 
added 
> to refrence but i wanna use it to develop gui in vb6 

There is no COM interface exported (there is no COM 
interface at all in the DLL, actually), all functions must 
be declared using "Public Declare Function foo 
Lib "libhttrack.dll" (..) As .." - but I don'y even know if 
this is possible using functions using C-convention 
(not "WINAPI")