determine if an input is a palindrome

public static bool IsPalindrome(string input)
{
    int min = 0;
    int max = input.Length - 1;
    while (true)
    {
        if (min > max)
        {
            return true;
        }
        char a = input[min];
        char b = input[max];
        if (char.ToLower(a) != char.ToLower(b))
        {
            return false;
        }
        min++;
        max--;
    }
}

IsPalindrome("racecar")