How to Lock Mouse & Keyboard on a network

Please help me create a program that will lock the mouse and keyboard in a network when the time expires on it. example : the user want to use the PC for an hour, after an hour the program will automatically lock the mouse and keyboard as the time expires.

Please I need it very urgent........

Do you mean to say that you want the computer locked after a certain amount of time?
... why not use the screen saver with a password?

--Johnny