DOM Functions

HTML

<div id="clickme">Insert New</div>
<div id="test">You can change my background</div>

CSS

div{
    border:1pt solid black;
    height:100px;
    width:100px;
}

JavaScript

$("#test").click(function(){
    $(this).css("background","#CCCCCC");
});

$("#clickme").click(function(){
    $("body").append("<div id=\"test\">My background isn't changeable!</div>");
});