Add/Remove class

Add/Remove class

I am trying to make a navigation menu that when a link is clicked, loads content into a hidden div, then shows the hidden div, then changed the class of the list item. If the same link is clicked again the class reverts back to what it was before and then the content div becomes hidden.

Here is a url

Here is the Jquery
$(document).ready(function(){
$("a.1").click(function(){
$("div#hidden").load("/javatest/content1.html");
$("div#hidden").slideDown();
$("a").removeClass("1").addClass("1-change");
});
$("a.1-change").click(function(){
$("div#hidden").slideUp();
$("a").removeClass("1-change").addClass("1");
});
});

How can I get this to work?