Problem running prime number test.

Code:

`#include <stdafx.h>`

#include <iostream>

#include <math.h>

using namespace std;

int main()

{

int n; // Number to test for prime-ness

int i; // Loop counter

int is_prime; // Boolean flag

//Assume that a number is prime until proven

//otherwise

is_prime = true;

//Get a number from the keyboard.

cout << "Enter a number and press ENTER: ";

cin >> n;

//Test for prime-ness by checking for divisibility

//by all whole numbers from 2 to sqrt(n).

i = 2;

while (i <= sqrt(static_cast<double>(n)))

{

if (n % i == 0)

is_prime = false;

i++;

}

//Print results

if (is_prime)

cout << "Number is prime.";

else

cout << "Number is not prime.";

return 0;

}

This program was written in Visual C++ Express on a CLR Console Application template. The problem that I'm having is that the program won't run when I hit Ctrl+F5 and I get an error message that says 'There were building errors'. My guess is that the <math.h> library might not be included in the express edition or perhaps I haven't installed it or something. But I wanted to post it here just in case I was missing any obvious mistake that I'm not seeing.

NOTE: This is a noob programmer speaking. Been writing code for about 4 days total so keep that in mind.