I need urgent help with the following problem:

Suppose  there is a class  AirConditioner . The class  supports the following behaviors : turning the air conditioner on and off. The following methods  are provided for these behaviors : turnOn and turnOff . Both methods  accept no arguments  and return no value .
There is a reference variable  myAC to an object  of this class , which has already  been created. Send a message  to this object  using the reference variable , telling it to turn the air conditioner on.

I think the answer is:

sendMessage(turnOn);

but i'm worng.

PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!