Timing of C#

khalid khatri wrote:

e.g window xp if user can't take any acton of some time then screen saver are show

e.g mobile if user can't take any acton of some time then mobile are automatic lock

These are already handled by the operating system. For mobile devices this is usually a minute or less. For Windows, it's user definable, but you can kick off the screen saver programatically if you want to (google is your friend).

khalid khatri wrote:

i user can't take any action in 10 second at runtime then message box show

So write a thread that waits for the time limit, and then shows the messagebox. If the user takes an action before the thread expires, abort the thread, and restart it again after the user's action is complete.