A soft damp cloth with will work just fine. You can use a mild soap if necessary, just don't let the cloth be sloppy wet. Fluids finding their way off the screen and under the keyboard can cause you some real problems real quick. ...had a Coke spilled onto my laptop a few years ago. The guy who spilled it got lucky, as I knew how to take the machine apart, and was able to dry the area under the keyboard before the Coke damaged the electronics. He only had to buy me a new keyboard. Also, be gentle, excessive pressure on the screen is a no-no.

Bob