This compatibility fix intercepts calls made to the GetWindowLongA API and redirects them to the GetWindowLongW API to get ...

This compatibility fix intercepts calls made to the GetWindowLongA API and redirects them to the GetWindowLongW API to get the WindowProc address. This is because in Windows XP, the GetWindowLongA API does not return the "Window Procedure" address directly and the application has to use the CallWindowProc API to call the window procedure. This compatibility fix also works for the Dialog procedure.