1 WHEN_ERROR
 The WHEN ERROR statement marks the beginning of a WHEN ERROR  construct.
 The  WHEN ERROR construct contains a protected region and can include an
 attached or detached handler.

 Examples

 WHEN ERROR IN
     INPUT "Enter your hourly rate";hourly_rate%
          .
          .
          .
 USE 
     SELECT ERR
          .
          .
          .
     END SELECT
 END WHEN

 WHEN ERROR USE error_trapper
      INPUT "Enter your hourly rate";hourly_rate%
          .
          .
          .
 END WHEN
 HANDLER error_trapper
          .
          .
          .
 END HANDLER

2 Syntax

 With an Attached handler:

     WHEN ERROR IN
         protected-statement
         [protected-statement,...]
        .
        .
        .
     USE
         handler-statement
         [handler-statement,...]
        .
        .
        .
     END WHEN

 With a Detached Handler:

     WHEN ERROR USE handler-name
          protected-statement
          [protected-statement,...]
         .
         .
         .
     END WHEN
     HANDLER handler-name
          handler-statement
          [handler-statement,...]
         .
         .
          .
     END HANDLER