Can you elaborate on what you're seeing? I always test code before posting so I can tell you this works on my machine at least. To be clear, you should get a square white window, and when you left-mouse-down in the window it will report the coordinates in the top left. If you hold left-mouse-down and move the mouse it will draw pixels and report the current coordinates in the top centre, and when you release the left-mouse it will report the final coordinates in the top right.