public static void AddSecureCookie(string key, string value, DateTime? expiryDate)
{
DateTime ticketExpiryDate = expiryDate.HasValue ? expiryDate.Value : DateTime.Now.AddMinutes(10);
FormsAuthenticationTicket formsAuthenticationTicket = new FormsAuthenticationTicket(1, key, DateTime.Now,
ticketExpiryDate, true, value);
AddCookie(key, FormsAuthentication.Encrypt(formsAuthenticationTicket), expiryDate);
}