... NIL in FWH example: hwndClient = FindWindowEx(hWnd, 0, "mdiclient", NIL) DLL32 Function FindWindowEx Lib "user32" Alias "FindWindowExA" ( _ ByVal hwndParent As Long, _ ByVal hwndChildAfter As Long, _ ByVal lpszClass As String, _ ByVal lpszWindow As String) As Long DLL32 Function FindWindowEx ( ...