<!DOCTYPE html>src="//libs.baidu.com/jquery/1.10.2/jquery.min.js"$(document).ready(function(){$("button").click(function(){$("#span1").text($(window).width());$("#span2").text($(document).width());});});The width of this window is id="span1"unknown px.The width of this document is id="span2"unknown px.Return the width of the window and document elements