Display prime numbers

The program shows how to display prime numbers. Here two for loops are used.

#include<stdio.h>
#include<conio.h>
        void main()
        {
            int num,count,i,n;
            clrscr();
            printf("\n Enter a number:");
            scanf("%d",&n);
            printf("\n The prime numbers are:");
            for(num=2;num<=n;num++)
            {
                count=0;
                for(i=1;i<=num;i++)
                {
                    if(num%i==0)
                        count++;
                }
                if(count==2)
                    printf("%d",num);
            }
            getch();
        }