Display a tray with a cloth wrapped around four sides. The glass of milk on the is covered with a metal tube.

You lift the metal tube, the glass of milk VANISHES! While taking a bow, you accidently exposes the glass that is hanging behind the cloth.

He tries the trick again and the audience thinks the same thing will happen, but when he takes the cloth off the glass has completely VANISHED!

Supplied complete with Tray, Plastic Glass, Cloth and Metal Ghost Tube.