Code not working properly after int21 AH=4C [SOLVED]

I was working on a code for some time and it went smooth until I added a variable called [origin_color] and after that the terminat interrupt started working incorectly.
Basiclly the code needs to return back to the dos terminal after you press ESC, but it just hangs on instead.

after deleting most of the code but leaving some parts in the code still not works, example:

Code:

format mz

entry code:start


segment varseg
        black_color db ?
        green_color db ?
        orgin_color db ?

        mouse_status db ?
        mouse_x dw ?
        mouse_y dw ?
        previous_x dw ?
        previous_y dw ?
        two dw ?


segment code
        start:

                mov [two], 02h
                mov [green_color], 02h
                mov [orgin_color], 09h

                mov ax, 13h
                int 10h

                main_loop:
                        keyboard_input:
                        in al, 60h
                        dec al
                        jz exit
                        jmp main_loop

        exit:

                mov ah, 4ch
                int 21h

if you erase

Code:

                mov [two], 02h
                mov [green_color], 02h
                mov [orgin_color], 09h

the code suddenly works.

Can someone explain why its happening, and how can I fix it? Crying or Very sad

edit1:

Following in a debug you find that that code runs until you press 'esc', then the IP jumps to 'exit' where it suppose to terminate the program and return, but after int 21h it just stacks Sad

and I searched for sometime for an answer in google and in the search in this board and could'nt find anything as the FAQ suggested.