Hp Officejet 6480 offline while wireless issue?

I just hooked up a new wireless router. The printer is already wireless. When I go to print, it says that the printer is offline. What the heck does offline mean anyways? How do I get it back online. I troublshot....rebooted everything...router, cable modem, laptop, printer....nothing helps. i even made sure the mac address for the printer was in the router setup. hmmmm any help is appreciated. tx.