diff -r dfe97199f17e -r 149244d86bf1 netserver/HWProto.hs
--- a/netserver/HWProto.hs	Wed Apr 30 20:18:30 2008 +0000
+++ b/netserver/HWProto.hs	Wed Apr 30 20:48:12 2008 +0000
@@ -3,12 +3,25 @@
 import IO
 import Miscutils
 
-handleCmd :: ClientInfo -> [ClientInfo] -> [RoomInfo] -> [String] -> ([ClientInfo], [String])
+handleCmd :: ClientInfo -> [ClientInfo] -> [RoomInfo] -> [String] -> (ClientInfo, [RoomInfo], [ClientInfo], [String])
 
-handleCmd client clients _ ("QUIT":xs) =
+
+handleCmd client clients rooms ("QUIT":xs) =
 	if null (room client) then
-		([client], ["QUIT"])
+		(client, rooms, [client], ["QUIT"])
 	else
-		(clients, ["QUIT", nick client])
+		(client, rooms, clients, ["QUIT", nick client])
+
 
-handleCmd client _ _ _ = ([client], ["Bad command"])
+handleCmd client clients rooms ("NICK":newNick:[]) =
+	if not . null $ nick client then
+		(client, rooms, [client], ["ERROR", "The nick already chosen"])
+	else if haveSameNick then
+		(client, rooms, [client], ["ERROR", "Choose another nick"])
+	else
+		(client{nick = newNick}, rooms, [client], ["NICK", newNick])
+	where
+		haveSameNick = not . null $ filter (\cl -> newNick == nick cl) clients
+
+
+handleCmd client _ rooms _ = (client, rooms, [client], ["ERROR", "Bad command"])