>I wrote a piece of code in C and want to use it in FoxPro. How can I do that? Should I make .dll or .lib or something else ????

DLL are easy to integrate in Visual FoxPro. Or, more easy, you can build an OCX and use that instead.

However, this can done with native Visual FoxPro code but you might save a lot of time using what you already build in C for the specific request.