public static User Authenticate(String userID, string password)
 {
     UserHolder.UserObject = null;
     if (userDBManager.Contains(userID))
     {
         if (userDBManager.Users[(Int32)userDBManager.UserIDSet[userID]].Password.Equals(password))
         {
             UserHolder.UserObject = userDBManager.Users[(Int32)userDBManager.UserIDSet[userID]];
         }
     }
     return(UserHolder.UserObject);
 }