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31 lines
748 B
Markdown
31 lines
748 B
Markdown
The [_SCREENEXISTS](_SCREENEXISTS) function returns true (-1) once a screen has been created.
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## Syntax
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> screenReady%% = [_SCREENEXISTS](_SCREENEXISTS)
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## Description
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* Function returns true (-1) once a program screen is available to use or change.
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* Can be used to avoid program errors because a screen was not ready for input or alterations.
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* Use before [_TITLE](_TITLE), [_SCREENMOVE](_SCREENMOVE) and other functions that require the output window to have been created.
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## Example(s)
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The loop busy-waits until the screen exists to add the title.
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```vb
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SCREEN 12
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DO: LOOP UNTIL _SCREENEXISTS
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_TITLE "My Title"
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```
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## See Also
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* [_FULLSCREEN](_FULLSCREEN)
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* [_SCREENIMAGE](_SCREENIMAGE)
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* [$CONSOLE]($CONSOLE)
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* [$RESIZE]($RESIZE)
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