Yeah, on my laptop's keyboard I have this tendency to write my destructors as:
The screen doesn't matter much for programming. What matters most is the keyboard. If the notebook doesn't provide an intuitive keyboard (i.e. the insert, delete, pageup/down, home and end keys are in stupid positions, perhaps even some other keys), stay away from it.
However, if the laptop is too large, it ceases being portable, in which case one might as well get a desktop computer.
If you can actually find a laptop with 19 inch (I don't think I've ever seen one), then you should have no problems with the keyboard, I believe. 17 inch do exist and are very nice. Have one myself.