Now you can check for a new version of the iPhone software.
Double click on the iPhone icon in the menu on the left side of the iTunes screen to open the iPhone Summary screen.
In the middle of the screen, you'll see a section called "Version." This tells you what version of the iPhone software your phone is running. If a newer version of the iOS is available, you'll see a button that says "Update." Click this to continue.
If you see a button that says "Check for Update," that means iTunes has not automatically found a newer version of the iOS software. Click this to manually check for an update; if your iPhone is already running the most current version, you'll see a pop up message saying "This version of the iPhone software (2.2.1) is the current version." That means no updated software is available.