When unlocking an iPhone 4S does it delete all the pics, messages etc?

Okay so I'm thinking of getting my iPhone unlocked from Vodafone to 3, but will it delete all my photos, messages, etc?

If you back up the data first on your iTunes, you won't lose the data. If you need help with getting the phone factory unlocked without losing any data, mail me for references.

No, but at the same time backup your phone anyway.