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'This example uses the UEVENT and ON UEVENT statements to enable
'user-defined event trapping. The SetUEvent routine signals a
'user-defined event, and control is passed to an event-handling
'routine. This example is a primitive use of the UEVENT statements,
'which are best suited for interfacing hardware to a computer.
 
'Note: In order to use this program or any user-defined event trapping,
'you must load the Quick library QBX.QLB using the /L option.
 
CLS
PRINT "This program asks for 10 numbers between 0 and 9, inclusive."
PRINT "As each number is input, it is evaluated to determine whether"
PRINT "it is odd or even. Odd numbers cause a user-defined event"
PRINT "to occur. Even numbers do not.": PRINT
ON UEVENT GOSUB Event1
UEVENT ON
DO
    PRINT "Enter a number --> ";
    N = VAL(INPUT$(1)): PRINT N: PRINT
    SELECT CASE N
        CASE 1, 3, 5, 7, 9
            PRINT "An odd number was input causing a user-defined event.";
            CALL SetUEvent
        CASE ELSE
            PRINT "No user-defined event occurred.": PRINT
    END SELECT
    LoopCount = LoopCount + 1
LOOP UNTIL LoopCount = 10
END
 
Event1:
    PRINT "Now processing the UEVENT. The odd number was"; N
    PRINT
    RETURN