How do I use the navigation feature in my Scion tC?

I just got this car about 4 days ago. It's a 2011. On the radio, there is a button that says "nav" for navigation. When I press it, nothing happens. Was there something else I needed to purchase in order for it to work? I wasn't the one who got the car, so I wasn't able to ask the sales associate. Does the navigation feature come standard, or do I have to purchase something else?

?2014-05-22T15:12:02Z

Jemery,

It's simply a standard equipment switch. It does not necessary mean you tC came equipped with a navigation system. It's a standard switch to be use if it indeed had such a feature which obviously yours does not.