I am trying to call a function in a C# program from a native Dll. The siganture is - BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved) I think I know that DWORD is an Int32 and LPVOID is a long pointer, so I'm using long* for that, but I'm not sure what type HINSTANCE should be. Can anyone tell me what this means. Thanks for any help. Declan.