After declaring the DLL functions I can call the functions in a simple prg. They return the correct information and have no errors. I created form that has text boxes. In the Textboxs valid event I copied the simple prg. It doesn't work, I get a page fault error and everything shuts down. I then changed the Valid event to call the simple prg as a function (Do Fcheck()) Now the form returns "invalid subscript". I do not have an array defined. The function does not call for an array either. Can I call DLL's from inside the Valid event? Help?