The _SCREENEXISTS function returns true (-1) once a screen has been created.
screenReady%% = _SCREENEXISTS
- Function returns true (-1) once a program screen is available to use or change.
- Can be used to avoid program errors because a screen was not ready for input or alterations.
- Use before _TITLE, _SCREENMOVE and other functions that require the output window to have been created.
The loop busy-waits until the screen exists to add the title.
SCREEN 12 DO: LOOP UNTIL _SCREENEXISTS _TITLE "My Title"