Name your fiddle

Description

HTML

<ul id="nav">
    <li><a href="#panel1" class="current">Panel 1</a></li>
    <li><a href="#panel2">Panel 2</a></li>
    <li><a href="#panel3">Panel 3</a></li>
</ul>

<div id="panel1" class="panel current">This is panel 1</div>
<div id="panel2" class="panel">This is panel 2</div>
<div id="panel3" class="panel">This is panel 3</div>

CSS

a.current { color: red; }
div.panel { display: none; }
div.panel.current { display:block; }

JavaScript

$('#nav a').click(function(e) {
    e.preventDefault();
    var panel = $(this).attr('href');
    $(this).addClass("current");
    $("a", $(this).parents("li").siblings("li")).removeClass("current");
    // show slide
    $(this).parents("ul").siblings("div").hide();
    $(panel).show();
})