Examples

   1.$ IF P1 .EQS. "HELP" THEN GOTO TELL
     $ IF P1 .EQS. "" THEN GOTO TELL
        .
        .
        .
     $ EXIT
     $ TELL:
     $ TYPE SYS$INPUT
     To use this procedure, you must enter a value for P1.
        .
        .
        .
     $ EXIT

     In this example, the IF command checks the first parameter
     passed to the command procedure; if this parameter is the
     string HELP or if the parameter is not specified, the GOTO
     command is executed and control is passed to the line labeled
     TELL; otherwise, the procedure continues executing until the
     EXIT command is encountered. At the label TELL, a TYPE command
     displays data in the input stream that documents how to use the
     procedure.

   2.$ ON ERROR THEN GOTO CHECK
        .
        .
        .
     $ EXIT
     $ CHECK:  ! Error handling routine
        .
        .
        .
     $ END:
     $ EXIT

     The ON command establishes an error-handling routine. If any
     command or procedure subsequently executed in the command
     procedure returns an error or severe error, the GOTO command
     transfers control to the label CHECK.