Chatbox - minimize and maximize buttons?

1. Is it possible to make min. and maximize buttons on chatbox like in windows top right corner?
Like in photo (top right in red rectangle):



And with this buttons we dont need "Join the chat" in bottom of forum,this button is not visible for my members.

2. I need like other people on forum, information about new chat message (sound or pop-up), I mistake many message on chat.

Sorry for my bad English,
you work good job on this forum...Thanks.