i'm using asp.net with c# to create an online Exam ... one of the security stuff i wanna implement is that when the student is taking the exam he won't be able to switch to another window in his pc means the asp page has to be maximized and the student won't be able to resize it other important thing he can't use any of the keys on the keyboard to access the start menu or search his pc.

so how can i lock the screen on that page without letting it lose the focus until the student is done from his exam ..

please help me
thanks