Check if a key is pressed by the user.
Unlike the simple version PRESS: does not take into account automatic key repeatition.
Returns a value of 1 for true,
0for false.
press once k
k key
Value Description A-Z ... character left left cursor right right cursor up up cursor down down cursor tab tab del delete delete backspace enter enter space space esc escape escape escape
Source if (press once "b") = 1 background (dice 1 to 99) end