Wap to erase vowels from given string

DECLARE FUNCTION ERA(A$)
CLS
INPUT"ENTER ANY STRING";A$
PRINT"STRING WITHOUT VOWELS =";ERA(A$)
END

FUNCTION ERA(A$)
FOR I = 1 TO LEN (A$)
B$=MID$(A$,I,1)
C$=UCASE$(B$)
IF C$<>"A" AND C$<>'E" AND C$<>"I" AND C$<>"O" AND C$<>"U" THEN D$=D$+C$
END IF
NEXT I
ERA=D$
END FUNCTION