Chat Section required like facebook

Hello every one, We are creating a community website and there we need a chat section just like Facebook has. We have a bottom bar created at footer that works pretty well and interested from coders to incorporate chat section over that bar. If any coder is interested to create his own bar he must make sure it work well (shouldn't overlap any thing and should stay at bottom). For the chat section you need to use AJAX, javascript, php. It should be easy to implement on any site. Make sure the chat window that appear on page should be move-able around the page. More options regarding this will be discussed later with interested coders. More work will come for coders that will perform well on this job... Happy bidding.