Iphone loses connection like every 2 min?

So i live in LA which i think has nothing to do with it lol. So my iphone 4 loses connection like every 2 or 3 min i have no clue what it is i'm really getting angry over it please help me what is this problem i have. Is it where i live or something or is it some kind of setting?

Maybe it's the fact that your phone has roaming so it changes servers automatically.

That doesn't seem right. The only person that can really answer that is someone at the store where you got your phone from.