不要了h 20、第 20 章

attr('href');

const index_page = $('#info_url').attr('href');

const next_page = $('#next_url').attr('href');

function jumpPage(){ const event = document.all ?

window.event : arguments[0];

if (event.keyCode == 37) document.location = preview_page;

if (event.keyCode == 39) document.location = next_page;

if (event.