Assuming that your laptop is functioning properly, you should switch among different display/output modes.
Just like what ibleet said, you should find the keys or buttons yourself, as this varies.
Typically, there is a button with the symbol like the picture attached.
In my case, I need to press Fn (Function) + F7 to activate the window showing me the various modes of display.
(I'm using Lenovo 3000 N100)
Hope this can help you, rustix.http://inlinethumb10.webshots.com/30473/2279374630071957632S200x200Q85.jpghttp://inlinethumb09.webshots.com/32008/2748211950071957632S425x425Q85.jpg