Get smart with the Thesis WordPress Theme from DIYthemes.
its old article but it works perfectly, thanks dave.
In most cases, the box class is useful outside of the content as well, so be sure to check your Skin’s documentation to see where you can use this handy formatting class.
To enable the Thesis nav menu, go to Thesis → Site Options ( click here for an image ). Under “Navigation Menu,” choose “Thesis nav menu” and then under “Pages,” check off the pages you want to include in your menu ( click here for an image ).