# File lib/capybara/session.rb, line 25
    def driver
      @driver ||= begin                    
        string = mode.to_s
        string.gsub!(%r{(^.)|(_.)}) { |m| m[m.length-1,1].upcase }
        Capybara::Driver.const_get(string.to_sym).new(app)
      rescue NameError
        raise Capybara::DriverNotFoundError, "no driver called #{mode} was found"
      end
    end