Are you asking how to see someone else's friend code? You'll need to use the "My Friend Codes" link over to the left.
Here is the documentation for this feature:
Friend Code Requests page contains a form to request other people's friend codes. You can do this in two ways. You can select one of your buddies by using the dropdown list next to where it says 'Select a Buddy' or you can enter in their username into the the box next where it says 'Enter User Name'. You also have the option of providing a short message in the 'Message' box. After doing this you only need to click on the Send Request button and the other person will now receive a Friend Code Request alert.
If they accept your request, you can view their friend code by clicking on the My Friend Codes link.
rain drop, drop top
The name's Jason.