Error handling is developed in user-written procedures. All of the built-in
procedures may return an error, warning, or information codes. The current
interface procedure, called the built-in procedure, determines the action that will
be taken as a result of an error. See the ON_ERROR... ENDON_ERROR statements
section for a description and syntax of the error handler. For more information on
error handling, see the on-line help.
Error Handling