Issue with key codes

I don’t get any errors from this code, however, it does nothing.
Any help would be greatly appreciated.


protected function keyPressHandler(event:KeyboardEvent):void
		{
			switch( event.keyCode )
			{
				case (event.keyCode == 87):
					upkeydown = true;
					break;
					
				case (event.keyCode == 65):
					leftkeydown = true;
					break;
					
				case (event.keyCode == 68):
					rightkeydown = true;
					break;
				
				case (event.keyCode == 83):
					downkeydown = true;
					break;
			
			}
		}