I have a function that I need to call from a lot of different classes and functions throughout my application. When I place the function in a header file and include that header file in all the classes, I get a link error saying the function has already been defined. I use the #if !defined, #endif... statements but that doesn't seem to help. How can I use this function in several places without having to duplicate the code? I am using MSVC++ 6.0. Thanks.