Start typing contact info in the box—even phone numbers or nicknames—and Yahoo! Messenger filters your list to show just the contacts in your Messenger List or Address Book that match what you've typed.
On the name of the contact you want, you can click either one of the following:
You can also click the person’s display image. Then, on the contact card that opens, click one of the links to call their mobile number, home number, work number, or send them an email. You'll see, it's easy!