Определить для строки а$ является ли она симметричной

INPUT "VASHA FRAZA-";A$
A$=LCASE(A$)
DIM B$(LEN(A$))
FOR I=1 TO LEN(A$)
B$(I)=MID$(A$,I,1)
IF B$(I)=" " OR B$(I)="," OR B$(I)="." OR B$(I)="-" THEN B$(I)=""
NEXT
FOR I=1 TO LEN(A$)
Q$=Q$+B$(I)
NEXT
FOR I=LEN(Q$) TO 1 STEP -1
P$=P$+MID$(Q$,I,1)
NEXT
IF Q$=P$ THEN ?"YAVLYAETSYA" ELSE ?"NET"

LINE INPUT "vvedite text: ", a$
FOR i = 1 TO LEN(a$)
    IF abc(a$, i) = 1 THEN buf$ = buf$ + MID$(a$, i, 1): f = 1
    IF (abc(a$, i) = 0 OR i = LEN(a$)) AND f = 1 THEN
        k = k + 1
        f = 0
        IF k = 1 THEN w$ = buf$
        IF k > 1 AND buf$ <> w$ THEN PRINT buf$
        buf$ = ""
    END IF
NEXT
FUNCTION abc (a$, i)
code = ASC(MID$(a$, i, 1))
IF (code >= 65 AND code <= 90) OR (code >= 97 AND code <= 122) THEN res = 1
IF code = ASC("-") AND i > 1 AND i < LEN(a$) THEN
    IF abc(a$, i - 1) = 1 AND abc(a$, i + 1) = 1 THEN res = 1
END IF
abc = res
END FUNCTION

INPUT "vvedite text: ", a$
FOR i = 1 TO LEN(a$) \ 2
    IF MID$(a$, i, 1) <> MID$(a$, LEN(a$) - i + 1, 1) THEN f = 1: EXIT FOR
NEXT
IF f = 0 THEN PRINT "stroka simmetrichna" ELSE PRINT "stroka ne simmetrichna"