I have duplicated a Visual c++ class from other people source code. There is no any errors when I compile my source code, but error "LNK 2001: unresolved external symbol" ocurr when I build the exe file.

I wonder what is the problem. I guess it is because I just copy the .cpp and .h file of the class and paste it to my source code.

Anybody could please help me? thanx

ty