Making skype like token field for adding users to a chat

In Mac, in skype when we add users to an existing chat, by clicking '+' button on top, a beak like window appears carrying a token field like control. When an user types some name in it and a match is found then a list appears carrying user icon , status icon and his/her name. Also the width of dynamic list is same as beak开发者_运维知识库 window.

Can any one suggest some way to create similar control?

Thanks in advance,

Miraaj

NSTokenField.

The control for the list would be NSTableView.