I have been laboring with similar issues myself of late. I found the following book a great help:- Visual FoxPro 5 - Enterprise Development by Paddock, Talmage & Petersen ISBN 0-7615-0903-8 Prima Publishing Good luck, Gerry > >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 > > ========================================================== Gerry Filby gerf@dmscomp.com Tel & Fax (212) 343 1201 dMS Computer Systems Tel (212) 580 0236