>Hi,
>
>Need Suggestion.
>I want to lock my application when user doesn't has activity
>on his/her mouse and keyboard for specified time.
>
>My question is how can I detect that keyboard and mouse hasn't activity.
>
>any tips and tricks will be very appreciate.
>thanks.

I am not sure what you mean by "Lock my application", but this class may help get you started (AutoClose form after N seconds). It closes a form if there has not been any activity for N seconds.

http://www.GLRsoftware.com/download.asp#AutoCloseForm.zip