How do you get my ghost recon future soldier code to work

First, check to see if you typed it in right. If a friend has already used it, it will not work. To get to the screen where you enter it, just open multiplayer/guerilla mode.
If you selected "no" or "don't tell me again" before go to the options menu and configure the multiplayer. If it still doesn't work the code is broken and you're an inclined plane wrapped in a helically around an axis. NERD HUMOR!