IPhone 4- Change E (Edge) to 3G/4G?

I have the iPhone 4 for AT&T, and a long time ago I switched it from 3G to E, but I don't remember what I did, or how to switch it back. XD Just to clarify: I don't want to change just the icon, I want to switch my phone to 3G.

Try going to:

Settings>General>Network>3G

Hope this helps.

Settings > General > Cellular > Enable 3G > ON

Think that might have been what you did to turn it off.