Stocks Update

my 3gs is jailbroken, can i just click update to new os in itunes to restore to stock?
so i love my jailbroken iphone 3gs, but id much rather have mms capabilities. do i just click update in itunes? would i lose all my stored stuff on my iphone?
i just want to know the easiest way to update without losing my stuff.
Click the Restore button on itunes when your iphone is plugged in. It will say restore and update. Click yes and it will do it in about 5-20 minutes depending on your computer speed. You will lose all your stuff on your phone itunes,photots,contacts. But you can just add them all back in on itunes after it is restored.
Hope this helped!
Business Update: Stocks surge