reference / input
held
Whether the key or mouse button with this name is held down right now: held "space", held "left" (the arrow key), held "mouse right". Keys have the names of on key; buttons are mouse left, middle, right, back and forward.
x = 200draw [ background 240 if held "left" [ x = x - 4 ] if held "right" [ x = x + 4 ] circle at x 150 radius 30 fill gold]
How to write it
held key
Gives true or false.