E-Mail address widget from Hotmail

When emailing someone from hotmail, the "To" field has a widget where individual email addresses are automatically encapsulated in a the closable box.

What is this widget or control called?

Can I downnload or purchase this control from anywhere?

From stackoverflow

• Gmail has also the same feature. Yahoo has also, I guess. It's based on auto-completion of your contact list in to/cc/bcc box.

  Yahoo! UI Library: AutoComplete

  AutoComplete Widget :: Basic JSON Implementation

  Hemal Pandya : Niehter of yahoo and google widgets are "encapsulated in a closable box'. Are you sure you know what the OP is talking about?

  dincer80 : If the question's about "auto-completion" feature (which is imho) then neither of them have closable boxes. On the other hand, if the question is about the onclick event of To button, then my answer may not be correct. (btw,Yahoo also brings contacts in a closable box after clicking To button)

  Hemal Pandya : @dincer80: I wonder why you thought @rashid's was question about auto-completion feature, since the question does not mention auto-completion. It *does* mention <> which is not what the To button is about

  dincer80 : @Hemal Pandya: You're right. I read the question again and now I'm sure I misunderstood the question. Probably it's because of reading fast. Also, when the words "To" ,"mail", "widget" are together, it directly reminded me the autocomplete feature. Sorry for wrong direction.