jQuery Forum

I need help with a template that I want to customize. Please visit http://air4.edev.me/ before we proceed.

The About page in the menu on the left loads another .php file ( about_us.php) which contains the text for 'About Us'.. This seems to reload the browser in order to display the html contained in about_us.php -- What I would like is the 'About Us' content to 'slide' down the page, without a page reload - containing the text/html/stylesheet from about_us.php....
I would like this done for all pages, I'm sure if I figure out the first one - the rest will be simple enough.

Here's login details to the development copy of the site. Please login and checkout how the website operates, and please tell me the best way to go about doing what I am trying to do.