Sliding Jquery Menu question

Sliding Jquery Menu question

I am trying to figure out how to get this slide out Jquery menu to work. Here is a link to what I am doing 


I will describe what I am trying to accomplish.

1. When you click on a link, the content related to that link dynamically loads into a slide out Div (this has been accomplished)
2. When you click on another link after the previous action the menu stays visible but loads the new content (this has been accomplished)
3. When you click on the same link a second time it closes the menu (this is what I cannot figure out how to accomplish)

I am fairly new to using Jquery and would appreciate any suggestions on how I could go about making step three happen for this menu.

Sincerely,

Scott