8queens.rb
# check quit-program by esc button

check quit-program by esc button
check quit - program by esc button
def button_down(id)
        if id == Gosu::KB_ESCAPE
            close
        else
            super
        end
    end
def button_down ( id ) if id == Gosu :: KB_ESCAPE close else super end end
check quit-program by esc button
check quit - program by esc button
id