using a laptop-screen in a standard desktop pc is not that easy... The laptop needs a driver-board (or something) which is normally built in to the casing of the screen, but in a laptop is built into the bottom part of the device (where the keyboard is)
So to connect a laptop screen to your normal pc you will need to either get that board out or buld a new driver board for it. This takes a lot of time and effort so you'll probably be better of buying a standard lcd screen.
At least that is what I know, maybe in the last two months someone has found another way to connect a laptop screen, in that case; I would like to know. I have a 14.1" screen laying around here...