Two Monitor Problem

Hello,
i have a GigaWare adapter for two monitors and i have them both hooked up, but it only recognizes the main monitor.the adapter has two cords running to the computer and then there is a little box that i plug the two monitors into. the two cords going into the computer are different. one looks like a VGA cable input and one looks like an audio input that u put in the TV when you are playng an old movie tape off a camera. im confused...