Setting structures in VFP is relatively complicated, you have to know how each type is represented in memory (in C) and packk all this to a VFP String There is a simple class to simplify this process on the VFUG downloads (and a couple of articles on the subject) IAC, you can always return here with specific questions Arnon > >I have a C header file that declares several structures to be used in API calls to a dll. If I include this header file in fox, can I use these structures in the API calls? If not, how can I set up structures in fox to allow me to make these calls? > >TIA