DECLARE FUNCTION IsPangram! (sentence AS STRING)

DIM x AS STRING

x = "My dog has fleas."
GOSUB doIt
x = "The lazy dog jumps over the quick brown fox."
GOSUB doIt
x = "Jackdaws love my big sphinx of quartz."
GOSUB doIt
x = "What's a jackdaw?"
GOSUB doIt

END

doIt:
    PRINT IsPangram!(x), x
    RETURN

FUNCTION IsPangram! (sentence AS STRING)
    'returns -1 (true) if sentence is a pangram, 0 (false) otherwise
    DIM l AS INTEGER, s AS STRING, t AS INTEGER
    DIM letters(25) AS INTEGER

    FOR l = 1 TO LEN(sentence)
        s = UCASE$(MID$(sentence, l, 1))
        SELECT CASE s
            CASE "A" TO "Z"
                t = ASC(s) - 65
                letters(t) = 1
        END SELECT
    NEXT

    FOR l = 0 TO 25
        IF letters(l) < 1 THEN
            IsPangram! = 0
            EXIT FUNCTION
        END IF
    NEXT

    IsPangram! = -1
END FUNCTION