How to get the iphone 3g on Wi-Fi?

My sisters friend found her dad's iPhone 3g lying around, it doesn't have the option to go on Wi-Fi what can I do to get it to work? I've reset the settings and network settings nothing will work. The only thing I haven't done was reset the phone, but they don't want to erase the music on it.

Remove sim card and check Wi-Fi again.

iPhone 3G Users Experience Wi-Fi Problem after Upgrading to iPhone 3.0
1.Turn off Push Email in Settings and restart your iPhone
2.Reset network settings. Touch Settings -> General -> Reset -> Reset Network Settings.

Does the iPhone have a Wi-Fi address listed in Settings> General> About?
iOS: Wi-Fi or Bluetooth settings grayed out or dim
1. Switch to flight mode
2. Switch on Wi-Fi
3. Reboot
4. Connect Wi-Fi, wait for the icon to appear
5. Switch off flight mode

1.go to bluetooth settings and switch on bluetooth
2.wait for the bluetooth icon to come up
3.go to Wi-Fi settings and seeif your networks are there.