Hello World !!! I am having problem in my project regarding mouse click within a particulr area on GL surface screen...when I click on that particular area..mouse click generates windows coordinate like (200,349). It's hard to sense the mouse click in that area on GL surface screen....so how can I convert the GL units into windows coordinate. Plz help me.....I know the logics regarding game projects ...but it's complicated to apply those logics in learning new API packages..how they work ...help me ???