Click the Green Flag to start. If you just move the pointer (without pressing mouse button) the sprite alternately draws lines and blanks. The variable "pendown" shows the status of the pen. Earlier I thought there was a problem with this program: if you press the mouse button while moving the mouse, the sprite moves, but the second script seems to freeze completely - the drawing stops and the variable also stays unchanged no matter how long you wait. But, now, the wiser, I know the problem. If you run the program in editor mode, the above problem shows up because clicking the mouse results in dragging the sprite. In full-screen mode this problem goes away!