run! (Merb::Authentication::Strategies::Basic::Form)

    # File lib/merb-auth-more/strategies/basic/password_form.rb, line 18
            def run!
              if (login = request.params[login_param]) && (password = request.params[password_param])
                user = user_class.authenticate(login, password)
                if !user
                  errors = request.session.authentication.errors
                  errors.clear!
                  errors.add(login_param, strategy_error_message)
                end
                user
              end
            end