Assemble Subtraction WITH MESSAGES

.MODEL SMALL
.STACK 100H
.DATA
    MSG1 DB 10,13, 'ENTER THE FIRST NUMBER : $'
    MSG2 DB 10,13, 'ENTER THE SECOND NUMBER : $'
    MSG3 DB 10,13, 'OUTPUT :$'

.CODE
MAIN PROC

    MOV AX, DATA
    MOV DS, AX

    LEA DX, MSG1
    MOV AH, 9
    INT 21H


    MOV AH, 1
    INT 21H             ;INPUT ONE
    MOV BL, AL

    LEA DX, MSG2
    MOV AH, 9
    INT 21H


    MOV AH, 1
    INT 21H             ;INPUT TWO
    MOV CL, AL

    SUB BL,CL
    ADD BL, 48 ;reduce when use big input as like 100 whose are greater than 9


    LEA DX, MSG3
    MOV AH, 9
    INT 21H

    MOV AH, 2
    MOV DL, BL     ;OUTPUT
    INT 21H

MAIN ENDP
END MAIN