Program to identify the prime number

Code:

#include<stdio.h>

#include<conio.h>

void main()

{

      int num,flag=0,a;

            printf("Enter an integer: ");

            scanf("%d",&num);

      //Logic for prime number

            if(num==2)

                  printf("%d is Prime Number.",num); 

            else

            {

                  for(a=2;a<num;a++)

                  {

                        if(num%a==0)

                              flag=1;

                  }

            }

            if(flag==1)

                  printf("%d is not a Prime Number.",num);

            else

                  printf("%d is Prime Number.",num);

      getch();

}

Result:

Enter an integer: 8

8 is not a Prime Number.

If you have any confusion about that program, contact me freely :)