Laptops can be a real pain, especially if not used correctly. OSHA has some suggestions for properly use.
Pain-free computing
Laptop users should use a docking station whenever possible. In the proper upright-sitting posture for computer use, the person's torso and neck are approximately vertical and in-line, the thighs are approximately horizontal, and the lower legs are vertical. For more information, visit the Occupational Safety and Health Administration's Good Working Positions page.
If you must use your notebook on your lap, find a chair that is comfortable to lean back and angle the screen so that you can see it with the least amount of neck deviation.