As long as you know your friend's username, you can find his/her profile in the member search page
Click "View Profile" and on the right side of your friends' homepage, you will see a link to "Add to my friends list".
This will send a message to your friend, which they can then accept or decline.
Whenever you are online at the same time, their username will show up on your homepage.
In Live Chess, once you and they are on each others friends list, every time they are in live chess, their username will appear in blue in the chatroom, and will show in your friends list tab in live chess, so you can find them there.
From the friends tab, you can either challenge friends or see if they are already playing, and watch their game using the "observe" link by their name.
If they are chatting in live chess chatroom, you can challenge them by clicking on their name, then on "Challenge"
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