Assembly language program to multiply two 16-bit nos

Mul.asm

store macro res
            div x
            mov res,dl;dividing and storing the last bit in dl i.e. is the remainder
            mov dx,0
endm

ansprint macro res
            mov dl,res
            add dl,30h
            mov ah,02h
            int 21h
endm

messageprint macro msg
            mov dx,offset msg
            mov ah,09h
            int 21h
endm

input macro variable
            mov ah,01h
            int 21h
            sub al,30h
            mov bh,al
            mov ah,01h
            int 21h
            sub al,30h
            mov bl,al
            mov variable,bx
endm

data segment
msg1 db "Enter  one number $"
msg2 db 10,13,"Enter  second number $"
msg3 db 10,13,"result =  $"

number1 dw 0
number2 dw ?
ans dw ?
carry dw ?

res db 8 dup(0)
x dw 10
data ends

code segment
assume cs:code,ds:data
start:
           
            mov ax,data
            mov ds,ax
           
            ;displaying the message
            messageprint msg1

           
            ;taking 8 bit of the 1st input number
            input bx
           
            ;combing two numbers
            mov ax,bx
            aad
            mov bx,0100
            mul bx
            mov bx,ax;number is in ax and storing it in bx
            mov number1,bx
           
            ;takin remaing 8bit of 1st number
            input bx
           
            ;combing two number
            mov ax,bx
            aad
            mov bx,ax
            mov ax,number1
            add ax,bx
            mov number1,ax;storing the first number in number1
           
           
            ;taking second number
            ;displaying the message
            messageprint msg2
           
            ;taking 8 bit of the 2nd input number
            input bx
           
            ;combing two numbers
            mov ax,bx
            aad
            mov bx,0100
            mul bx
            mov bx,ax;number is in ax and storing it in bx
            mov number2,bx
           
            ;takin remaing 8bit of 1st number
            input bx
           
           
            ;combing two number
            mov ax,bx
            aad
            mov bx,ax
            mov ax,number2
            add ax,bx
            mov number2,ax ;the second  number is stored in number2
           
           
            ;multiplying the two number
            mov ax,number1
            mov cx,number2
            mul cx
            mov ans,ax
            mov carry,dx
           
            ;storing the answer
            store res+7
            store res+6
            store res+5
            store res+4
            store res+3
            store res+2
            store res+1
            store res+0
           
           
            ;displaying the ans message
            messageprint msg3
           
           
            ;displaying the answer
            ansprint res+0
            ansprint res+1
            ansprint res+2
            ansprint res+3
            ansprint res+4
            ansprint res+5
            ansprint res+6
            ansprint res+7
           
           
           
            ;terminate the program
            mov ax,4c00h
            int 21h

code ends
end start