When you click on the categories menu here for example on "Boys " you get all the subcategories displayed in the left without opening a white page on the right. They remain in the same place.
http://www.modernmunchkin.com

When you click on the categories here, for example on "Annoucements/Invitations" you get a white page on the right with buttons of the subcategories.
http://cocoaprints.com

How can I do as the first sample? Not opening a page for each categorie but just displaying the subcategories menu on the left?

I would apreciate any help!