my iphone 4s doesn't make sounds any more

A few days ago my iphone 4S stopped working. It is not on silent. If someone calls me there is a ring tone but I don't get message alerts any more and I can't play music via my speakers. I can't adjust the volume via the buttons on the side of the phone. I tried connecting to iTunes and downloading a song as someone suggested this but it hasn't worked. My phone is not under warranty any more.