When you're chatting with a friend, you can change your avatar's expression to show how you're feeling. You can do this by typing key words or character combinations called "emoticons."
Click these links to see a list of emoticons your avatar can use:
As you use emoticons in IM conversations, your avatar's expression changes temporarily.
If you want to change your avatar's mood for longer, go to the Yahoo!7 Yahoo!7 Avatars site and pick a new mood from the Preview Window. Or in Yahoo!7 Messenger 6.0 and later, click your avatar above the Messenger List, then choose "Set Avatar Mood to" and pick a mood.