<head>
<script src="http://code.jquery.com/jquery.min.js" type="text/javascript"></script>
</head>
<body>
<div id="chat_users" style="display:none;">user1<br>user2<br>user3<br>user4<br></div>
<div id="chat_popup">CLIKNI TUK ZA CHAT</div>
<script type="text/javascript">
$("div#chat_popup").click(function() {
$("div#chat_users").fadeIn();
});
</script>
</body>