Nested loop

.model small
.stack 100h
.code
main proc
    mov cx,4
    level1:
    mov bx,cx
    level2:
    mov ah,2
    mov dl,'*'
    int 21h
    loop level2

    mov ah,2
    mov dl,10
    int 21h
    mov dl,13
    int 21h

    mov cx,bx

    loop level1

    main endp
end main