SYNOPSIS
error(message[,level])
DESCRIPTION
Terminates the last protected function called and returns message as the error message. Function
error never returns.
Usually, error adds some information about the error position at the beginning of the message. The
level argument specifies how to get the error position. With level 1 (the default), the error
position is where the error function was called. Level 2 points the error to where the function
that called error was called; and so on. Passing a level 0 avoids the addition of error position
information to the message.