This command pauses execution and waits for the user to touch the screen. The coordinates of the touch are stored in X and Y.
If the optional delay parameter is specified in milliseconds, the program will continue execution after that time. If the user did not touch the screen in that time X and Y will both be -1.
There is a buffer which holds touch events until they are read with the touch command. If you need to clear the touch buffer execute a touch command with a delay of zero. The touch buffer will be cleared and the last touched position is returned.