public static String Login(User user)
{
Certification certifier = Certification.GetInstance();
string value = Secret.DESEncrypt(user.Id + separator + Time.GetTimeStamp(DateTime.Now));
if (Certification.Certifier.ContainsKey(user.Id))
{
Certification.Certifier.Remove(user.Id);
}
Certification.Certifier.Add(user.Id, user);
return(value);
}