check prime

#include<stdio.h>
#include<conio.h>
void main()
{
	int n,i,m,p,flag=0;
	clrscr();
	printf("Enter the number:");
	scanf("%d",&n);
	i=2;
	do
	{
		if(n%i==0)
		flag=1;
		i++;
	}
	while(i<n/2);
	if(flag==1)
		printf("%d is not prime\n",n);
	else
		printf("%d is prime\n",n);
	getch();
}