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The SIGNAL statements enable, disable, or suspend event trapping for an
OS/2 protected-mode signal.
 
SIGNAL(n%) ON
SIGNAL(n%) OFF
SIGNAL(n%) STOP
    ■ The argument n% identifies a signal specified in a previous
      ON SIGNAL statement.
 
Usage Notes
    ■ SIGNAL(n%) ON enables trapping of OS/2 signal n%. If an OS/2 protected-
      mode signal occurs after a SIGNAL(n%) ON statement, the routine
      specified in the ON SIGNAL statement is executed.
    ■ SIGNAL(n%) OFF disables trapping of OS/2 signal n%. No trapping takes
      place until another SIGNAL(n%) ON statement is executed. Events
      occurring while trapping is off are ignored.
    ■ SIGNAL(n%) STOP suspends trapping of OS/2 signal n%. No trapping takes
      place until a SIGNAL(n%) ON statement is executed. Events occurring
      while trapping is suspended are remembered and processed when the
      next SIGNAL(n%) ON statement is executed. However, remembered events
      are lost if SIGNAL(n%) OFF is executed.
    ■ When a communications event trap occurs (that is, the GOSUB is
      performed), an automatic SIGNAL(n%) STOP is executed so that recursive
      traps cannot take place. The RETURN from the trapping routine
      automatically executes a SIGNAL(n%) ON statement unless an explicit
      SIGNAL(n%) OFF was performed inside the routine.
    ■ For more information, see Chapter 9, "Event Handling" in the
      Programmer's Guide.