ERRORLEVEL is set to the offset of the key that the user presses in choices.
The first key you assign returns a value of 1, the second a value of 2, the third a value of 3, and so on. If the user presses a key that is not among the keys you assigned, Choice sounds a warning beep (that is, it sends a BEL, or 07h, character to the console).
If Choice detects an error condition, it returns an ERRORLEVEL value of 255.
If the user presses CTRL+BREAK or CTRL+C, Choice returns an ERRORLEVEL value of 0.
When you use ERRORLEVEL parameters in a batch program, list them in decreasing order.