How I can change my code? Caeser cipher on tasm

 IDEAL
MODEL small
STACK 100h
DATASEG
MSG1 DB 'ENTER FIVE CHARACTER : $'
MSG2 DB 10,13,'RESULT : $'
ARR1 DB 5 DUP (00)
ARR2 DB 5 DUP (00),'$'
CODESEG
start:

	MACRO AL
    CMP AL,'z'
    JA exit
    CMP AL,'A'
    JB exit
    CMP AL,'Z'
    JE decrease
    CMP AL,'z'
    JE decrease
    CMP AL,'Y'
    JE decrease
    CMP AL,'y'
    JE decrease
    CMP AL,'X'
    JE decrease
    CMP AL,'x'
    JE decrease
    
    add al,3
    JMP exit
    ;-----------------------
    decrease:
    SUB AL,23
    JMP exit
    ;-----------------------
    exit:
endm
;--------------------------------------------------
    
     MOV AX,@DATA
     MOV DS,AX 
     
     LEA SI,[ARR1]
     LEA DI,[ARR2]
     
     ;PRINT MSG1
     LEA DX,[MSG1]
     MOV AH,09
     INT 21H
     
     MOV CX,5   ;NUMBER OF CHARACTER IN WORD  
     
     INPUT:
     MOV AH,01
     INT 21H
     MOV [SI],AL
     INC SI
     LOOP INPUT
     
     ;--------------------------------------
     MOV DX,0000
     MOV CX,5
     LEA SI,[ARR1]
     
     OUTPUT:
     MOV AL,[SI]
     main AL
     MOV [DI],AL
     INC SI
     INC DI
     LOOP OUTPUT
     
     ;------------------------------------------               
     LEA DX,[MSG2]
     MOV AH,09
     INT 21H
     LEA DX,[ARR2]
     MOV AH,09
     INT 21H
exit:
	mov ax, 4c00h
	int 21h
END start