I have an iPhone 4s, and I recently reset it. Now I'm unable to sync to my iTunes?

My iPhone 4s was giving me some trouble and my friend suggested that I reset it, so I did. I'm not able to sync any of the songs from iTunes (and I have like 1, 500!) I realize that this is not a huge deal because I have an iPod with music on it, but I love being able to just have my phone and have everything in one place. I'm able to sync the iPod to iTunes, just not my phone. I have tried syncing it over and over to the same result. I have spoken to apple and they don't even know what to do.

What do you mean by not working? Syncing works but music adding doesn't? If syncing doesn't work then try restoring the iPhone (all data will be deleted). If music isn't added, maybe you disabled music syncing… Go to your iPhone on iTunes and click on Music at the top and check sync music, then press apply and sync.