Input letter and displaying the corresponding output

[Jezer]

Hello i am creating the assembly program that accepts a single character and display the alphabet . The requirements are (1) The input character should be displayed (2) The input of the single uppercase letter should be displayed the lowercase letter. (3) The alphabet should be displayed horizontal position and (3) Only the letter 'X' should be accepted as input.

I managed to let the program when input a uppercase character and displayed the alphabet in lowercase letter however, it displayed vertically position and also the displayed uppercase letter. I don't know to how figure out, Can somebody help me to on this topic... Thank you

.model small
.stack
.data
    input db "Input a Uppercase Character -> $"
.code
org 100h

start:

    main proc

        mov ax,03
        int 10h

        mov ax,@data
        mov ds,ax

        mov ah,9     
        lea dx, input
        int 21h

        mov ah,01
        int 21h

        mov dh,al
                mov ah,02
                mov dl,13
                int 21h
                mov dl,10
                int 21h
        mov al,dh

        mov bl,al

        cmp bl, 'a'
        jb main
        cmp bl, 'z'
        ja main

        mov dl,al
        sub dl,20h

        mov ah,02
        int 21h

        mov cx,26
        mov dh,dl

            letters:

                 mov bx,cx
                 call down
                 mov dl,dh

                 cmp dl,'Z'
                 je exit

                 inc dl
                 int 21h
                 mov dh,dl
                 mov cx,bx
            loop letters

        mov ah,4ch
        int 21h
    main endp

            down proc
                mov dl,13
                int 21h
                mov dl,10
                int 21h
                ret
            down endp

            exit proc
                mov ah,4ch
                int 21h
            exit endp

end start

The output should be like this:
EVEN EVEN

Input: X

xyz