Threads don't speed things up. They slow them down, by causing your UI thread to also take process time. Having said that, what is your UI doing to use up that much time ? Nothend wrote: Thread.Sleep(30); Why force a sleep in a process that is already slow ? Christian Graus Please read this if you don't understand the answer I've given you "also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Thank you very much!

Thank you very much!The problem is solved!!! Thanks!

Thanks a lot ,it works!!! Nothend

Nothend wrote: If possiable,show me with a graph. Not sure how you expected that. GetWindowRect gets the rectangle that the windows takes up. ScreenToClient takes co-ordinates that relate to the entire screen, and converts them to co-ordinates that are relative to the top left corner of the client program specified. Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog

I have tried that ,but it would be error. It will show error dialog saying that "Debug Assertion Failed",and if I retry,the XP sends me a error report. Nothend