PostMessage fails if you pass in NULL as the HWND argument. According to the MSDN, a NULL HWND means "The function behaves like a call to PostThreadMessage with the dwThreadId parameter set to the identifier of the current thread." Currently, PostMessage tries to get the thread id of the hwnd, which of course fails since it's NULL in this case, and of course the error is Invalid Window Handle.
It seems like a simple fix is a test if hwnd is NULL and calling PostThreadMessage with the right thread ID, but I don't know how to get the current thread's ID. Any ideas/suggestions? -Steve
