QBASIC to count total number of vowels in words using FUNCTION

DECLARE FUNCTION COUNT ( N$ ) 
CLS
INPUT "Enter any word"; N$
PRINT "Total number of vowels = "; COUNT ( N$ )
END

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