ON TIMER                 Trap for Elapsed Time

 ON TIMER(n) GOSUB {linenum | linelabel}

    Establishes a subroutine to which Turbo Basic will branch if a
    specified number of seconds have passed. The trap must also be turned
    on by means of a TIMER ON statement.

           n    A numeric expression in the range 1 to 86,400 (1 second to
                24 hours).

     linenum    The first line of a timer-handling subroutine. Setting
                linenum to 0 disables trapping.

   linelabel    A label identifying the first line of a timer-handling
                routine.

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      Notes:    With trapping in effect, Turbo Basic checks to see if the
                specified number of seconds have elapsed. When the
                specified amount of time has passed, Turbo Basic branches
                to the specified subroutine and temporarily suspends
                trapping (by means of an implicit TIMER STOP statement).
                Trapping automatically resumes when a RETURN from the
                handling subroutine is executed (unless the handler
                explicitly performs a TIMER OFF or TIMER STOP).

                With event trapping in effect, Turbo Basic checks for the
                specified event after each program statement. The $EVENT
                metastatement can be used to turn event trapping on and
                off at specified points within a program.