Ok since there has been a problem with the format we are currently working at, Here's how you do the button.
Step 1: Check your user cp for friend request. First go to UserCP>Friends and see if you have any request.
Step 2: If you do have a request go to there profile and look at the image in step 3 to add them
Step 3:
Step 4: Click on the friends add and then it will add them as a friend.
Step 5: Your all set to go.