public void ChangePassword(int id, string oldPassword, string newPassword) { var user = _db.GetAll().SingleOrDefault(user => user.Id == id); if (user.Password != oldPassword) { MessageHelpers.ErrorMessage("Please enter a correct old password."); return; } if (oldPassword == newPassword) { MessageHelpers.ErrorMessage("New password can not be old password."); return; } if (ValidationHelpers.PasswordValidation(newPassword) == null) { MessageHelpers.ErrorMessage("Not a valid new password."); return; } user.Password = newPassword; MessageHelpers.SuccessMessage("Password successfully changed."); }