// JavaScript Document

$(document).ready(function() {
 
 alert($("#mainContent").html()); // alerts the contents of #maincontent
 
 $("h2:first").html('This is new <em>header</em> content'); //changes the content of the first H2
 
 alert($("#mainContent").text()); // alerts the contents of #maincontent
 
 $("h2:first").text('This is new <em>header</em> content'); //changes the content of the first H2
 
 });