Alright, I setup my primary window (the parent window) with the WS_CLIPCHILDREN style so that I could do some custom drawing in four or five of the child windows. The thing is, I only want to paint the child windows at specific times, such as when the user clicks inside of one. How can I tell which child window is sending a message to the parent about what is going on? For instance, I have a static window in the center of the parent window and when the user left-clicks in it, I want to place an image at the location the suer clicked. I know how to place the image and all, but I cannot figure out how to handle clicks in child windows, or how to tell those clicks from ones in the parent window, which should be ignored.