Need help

[Flipper15]

Hi, I need help with some C++, I bought a book and there's an example code which says if the number is prime or not, but it can only calculate the numbers 1, 2 and 3.Whenever I type in some other number it just freezes and doesn't do anything.
Here's the code, I want to know what I'm doing wrong:

#include "stdafx.h"
#include <iostream>
#include <cmath>
using namespace std;

int main()
{
	int n;
	int i;
	int is_prime = true;

	cout << "Type in a number and press enter" << endl;
	cin >> n;
	i = 2;
	while( i <= sqrt(double (n)) );
	{
		if( n % i == 0 )
		{
			is_prime = false;
			i++;
		}
	}
	if(is_prime)
		cout << "Number is prime" << endl;
	else
		cout << "Number isn't prime" << endl;
	system("pause");
	return main();
}

I would really appreciate if someone could help me with this.Thanks in advance.

[highlight](User was banned for this post ("undescirptive thread title" - postal))[/highlight]

[ZeekyHBomb]

The semicolon at line 15 (after the while) is incorrect. Remove it.

[Corewarp3]

All these easy beginner question threads recently makes me want to make a megathread so I can help people in a central place, rather than having to seek them out, or hope they find me xD

[supersnail11]

[QUOTE=Corewarp3;40360593]All these easy beginner question threads recently makes me want to make a megathread so I can help people in a central place, rather than having to seek them out, or hope they find me xD[/QUOTE]

[url]http://facepunch.com/showthread.php?t=1250528[/url]