C++ Program .Write a program to function with no argument & no return value.

#include<stdio.h>
#include<conio.h>
void add();
void main()
{
clrscr();
add();
getch();
}
void add()
{
int a,b,c;
printf("\n enter the value of a");
scanf("\n %d",&a);
printf("\n enter the value of b");
scanf("\n %d",&b);
c=a+b;
printf("\n addition is %d",c);
}