normal (brute force) method to check for primes

IsPrime.cs

bool IsPrime(long n)
{
    int c = 0;
    for (long i = 1; i < n; i++)
    {//loop up-till the number
        if (n % i == 0)//check if its divisible by i
        {
            c++;
            if (c > 1) { return false; }//short-circuit.. 
        }   //^^if it has more than one divisor it can't be prime
    }
    if (c == 1)
    {
        return true;
    }
    return false;
}