This has never been done before, so there is no chance that a quick google would find anything, is there? Pity that.
Might be worth a try though...
Good grief!
A very quick search <b><i>using your subject as the search term</i></b> gave 5,000,000 solutions! Who would have thought it!
http://www.google.co.uk/search?sourceid=chrome&ie=UTF-8&q=Create+Chat+Application+using+.net+framework[
^]
In future, please try to do at least basic research yourself, and not waste your time or ours.
Google is your friend: Be nice and visit him often. He can answer questions a lot more quickly than posting them here...