public bool ChangePassword(string user, string old_psw, string new_psw)
        {
            Database.SLW_DatabaseInfo db          = new Database.SLW_DatabaseInfo();
            Models.UserCredentials    credentials = db.GetUserCredentials(user);

            if (VerifyCredentials(old_psw, credentials.hash))
            {
                db.UpdatePassword(user, GetHash(new_psw));
                return(true);
            }
            else
            {
                return(false);
            }
        }