QBASIC to count total no. of constant using FUNCTION

DECLARE FUNCTION COUNT ( N$ )
CLS
INPUT "Enter any word"; N$
PRINT "Total no. of constant = "; COUNT ( N$ )
END

FUNCTION COUNT ( N$ )
C = 0
FOR I = 1 TO LEN ( N$ )
B$ = MID $ ( N$, I, 1 )
C$ = UCASE $ ( B$ )
IF C$ <> "I" AND C$ <> "O" AND C$ "U" THEN C = C + 1
NEXT I
COUNT = C
END FUNCTION