Use this function to get values from supported input devices. This values are greater zero and stored in the control code buffer and this buffer works like a first in first out queue.

%System.Input(Parameter)

GetCode - returns control code and deletes it from buffer, else 0 is returned
ReadCode - returns control code stored in buffer, else 0 is returned
BufferSize - returns the number of stored control codes in the buffer
ClearBuffer - clears the buffer

Example:

%System.Input(GetKey)