LCD Tv. Urgent help needed!?

Question

We recently bought a Sony Brava LCD Television. My little brother left his handprint right in the middle. It looks terrible, you cant see it when your watching TV, but when its off its very clear.

What can I use to wash it off? I dont want to use water it might wreck it.. or maybe it wont. What can I use? I need a right answer, not a "Oh maybe you could use..." its a very expensive tv and dont want to ruin it.

Please help.