I just got a 15" MBP and would like to hook it up to a 24" Dell Ultrasharp I inherited. However, I know nothing about the button settings on the monitor. When I connect the two, the MBP background shows up on the Dell monitor but the icons that run along the bottom of the MBP screen are cut off. I'm assuming I need to change the monitor settings but don't know what I'm doing. Can anyone help? Thanks very much!