Write an assembly language program that inputs a single letter and shows the same letter in it’s opposite case in a new line. (Lower-case to Upper-case or vice-versa)

DIS MACRO STR
MOV AH,09H
LEA DX,STR
INT 21H
ENDM
DATA SEGMENT
    MSG1 DB \"ENTER YOUR STRING : $\"
    MSG2 DB \"CONVERTED STRING IS : $\"
    STR1 DB 20 DUP(\'$\')
    LINE DB 10,13,\'$\'
DATA ENDS

CODE SEGMENT
          ASSUME DS:DATA,CS:CODE
START:
        MOV AX,DATA
        MOV DS,AX
        DIS MSG1
        MOV AH,0AH
        LEA DX,STR1
        INT 21H
        DIS LINE
        MOV CH,00
        MOV CL,BYTE PTR[STR1+1]
        LEA SI,STR1+2
    L1: MOV AH,BYTE PTR[SI]
        CMP AH,\'A\'
        JL L4
        CMP AH,\'Z\'
        JG L2
        ADD BYTE PTR[SI],32
        JMP L3
     L2:CMP AH,\'a\'
        JL L4
        CMP AH,\'z\'
        JG L4
        SUB BYTE PTR[SI],32
     L3:INC SI
        LOOP L1
        DIS MSG2
        DIS STR1+2
     L4:MOV AH,4CH
        INT 21H
CODE ENDS
END START

;------
;OUTPUT
;------

    ENTER YOUR STRING : JiNeSh
    CONVERTED STRING IS : jInEsh