iTunes not recognizing iPod as home iPod

Hi, I just bought a new ipod online after mine was drowned in the pool, and when I plug it into the usb port, instead of recognizing it as the home iPod for this computer and iTunes, it lists my library and then a few lines underneath, gives the name of my iPod and all the songs on it. So anytime I put more songs on my computer, I have to upload to iTunes Library and then drag everything onto my iPod. Does anyone know how to get it to recognize my iPod as the home one? Thanks!