On most laptops one can enable/disable a screen by pressing on one of
the F keys together with the FN key at the bottom. I don't know which F
key is the correct one for the Toshiba but the IBM laptops use F7. The
idea is to be able to interact with a projector enabling or disabling
the projector, computer screen or using them both. There should be a
"screen" drawing on the F key meant to be pressed with the FN key.