Help me, Clock with TASM

[coderKid]

Hi everyone
i am new here
and i have problem with this code, i need algorithm all code. please help me all master of Assembly :)

program has a bug. not change AM to PM in the right time. please help me to change. thank you so much. :)
especially this : ...

check_hour proc
xor ax, ax ; kosongkan ax agar tidak divide overflow
mov al, hour_num
cmp al, 13
jl siang ; (Jump If Less Than)
;jika 13 atau lebih maka dikurang 12 untuk membuatnya menjadi 1
sub AL, 12
mov am_pm, 80
JMP pagi
siang:
;else if hour is less than or equal to 12
mov am_pm, 65
pagi:
lea SI, hour_out
mov BL, 10
div BL
add AL, 48
mov DS:[SI], AL
inc SI
add AH, 48
mov DS:[SI], AH
ret
check_hour endp

full code:

    .model small
    .stack 200h
    .data
     hour_num db ?
     min_num db ?
     sec_num db ?
     hour_out db ' '
     batas1 db ' : '
     min_out db ' '
     batas2 db ' : '
     sec_out db ' '
     spacer db ' '
     am_pm db 'AM'
     ender db '$'

    .code
    Start:
     mov AX, @data ;khusus untuk program exe
     mov DS, AX ;arahkan register ds ke data segmen melalui register ax

     ;call procedures
     call get_time
     call check_hour
     call check_min
     call check_sec
     call create_box
     call print_time


     ;Mengecek isi keyboard buffer.
     mov ah, 0bh ;get input status menggunakan AL
     int 21h
     cmp al, 0 ; AL = 00h jika tidak ada karakter
     je Start

     call clear_screen

     ;set posisi cursor
     ;agar di sudut kiri atas
     mov ah, 02h
     mov bh, 00
     mov dh, 00
     mov dl, 00
     int 10h

     mov ax, 4c00h ; kembali ke DOS
     int 21h


    ; * PROCEDURES*
    clear_screen proc
     mov cx, 0
     mov dx, 7924 ; mengatur ukuran layar yg akan dihapus
     mov al, 0
     mov bh, 7h
     mov ah, 6h
     int 10h
    ret
    clear_screen endp

    get_time proc
     ;clear/scroll the screen
     mov ax,2c00h
     int 21h
     ;ch = jam
     ;cl = menit
     ;dh = detik
     ;dl = mili detik
     mov hour_num,ch
     mov min_num,cl
     mov sec_num,dh
    ret ; return to caller.
    get_time endp

    check_hour proc
     xor ax, ax ; kosongkan ax agar tidak divide overflow
     mov al, hour_num
     cmp al, 13
     jl siang ; (Jump If Less Than)
     ;jika 13 atau lebih maka dikurang 12 untuk membuatnya menjadi 1
     sub AL, 12
     mov am_pm, 80
     JMP pagi
     siang:
     ;else if hour is less than or equal to 12
     mov am_pm, 65
     pagi:
     lea SI, hour_out
     mov BL, 10
     div BL
     add AL, 48
     mov DS:[SI], AL
     inc SI
     add AH, 48
     mov DS:[SI], AH
    ret
    check_hour endp

    check_min proc
     lea SI, min_out
     xor AX, AX
     mov AL, min_num
     mov BL, 10
     div BL
     add AL, 48
     mov DS:[SI], AL
     inc SI
     add AH, 48
     mov DS:[SI], AH
    ret
    check_min endp

    check_sec proc
     lea SI, sec_out
     xor AX, AX
     mov AL, sec_num
     mov BL, 10
     div BL
     add AL, 48
     mov DS:[SI], AL
     inc SI
     add AH, 48
     mov DS:[SI], AH
    ret
    check_sec endp

    create_box proc
     ;set posisi cursor
     mov ah, 02h
     mov bh, 00 ; nomor halaman tampilan
     mov dh, 08 ; nomor baris
     mov dl, 21 ; nomor kolom
     int 10h
     ;buat border ats
     mov ah, 09h
     mov al, '-'
     mov bh, 00
     mov bl, 09
     mov cx, 40
     int 10h

     ;set posisi cursor
     mov ah, 02h
     mov bh, 00
     mov dh, 16
     mov dl, 21
     int 10h
     ;buat border bawah
     mov ah, 09h
     mov al, '-'
     mov bh, 00
     mov bl, 09
     mov cx, 40
     int 10h

     ;set posisi cursor
     mov ah, 02
     mov bh, 00
     mov dh, 9
     mov dl, 21
     int 10h
     ;buat border kiri
     mov ah, 09h
     mov al, '|'
     mov cx, 1
     int 10h

     ;set posisi cursor
     mov ah, 02h
     mov bh, 00
     mov dh, 9
     mov dl, 60
     int 10h
     ;buat border kanan
     mov ah, 09h
     mov al, '|'
     mov cx, 1
     int 10h
    ret
    create_box endp

    print_time proc
     ;set posisi cursor
     mov ah, 02h
     mov bh, 00
     mov dh, 12
     mov dl, 34
     int 10h
     ;cetak string
     mov ah, 09h
     lea dx, hour_out
     int 21h
    ret
    print_time endp

    end Start