Program to Reverse String in assembly language

This Program Reverse the string which user enter

.model small
.stack 100h
.DATA
AR1 DB 10 DUP (?)
S1 DB 10,13,"ENTER A STRING : $"
S2 DB 10,13,"REVERSE ARRAY : $ "
S3 DB 10,13,"STRAIGHT : $"
COUNT DB 0
.
MAIN PROC
MOV AX,@DATA
MOV DS,AX

MOV DX,OFFSET S1
MOV AH,9
INT 21H

MOV CX,10

MOV DX,OFFSET AR1
MOV SI,DX

MOV AH,1
INT 21H
FOR_1:
CMP AL,13
JE END_1

MOV [SI], AL
INC SI
INC COUNT
INT 21H
LOOP FOR_1
END_1:
MOV BYTE PTR [SI], '$'

MOV DX,OFFSET S2
MOV AH,9
INT 21H

XOR CX,CX

MOV CL,COUNT
DEC SI

MOV AH,2

FOR_2:
MOV DL,[SI]
DEC SI
INT 21H
LOOP FOR_2

MOV DX,OFFSET S3
MOV AH,9
INT 21H

MOV DX,OFFSET AR1
MOV AH,9
INT 21H

MOV AH,4CH
INT 21H
MAIN ENDP
END MAIN