(require 'erc)

;; joining && autojoing
(erc-autojoin-mode t)
;; check channels
(erc-track-mode t)
(setq erc-track-exclude-types '("JOIN" "NICK" "PART" "QUIT" "MODE"
                                "324" "329" "332" "333" "353" "477"))
;; don't show any of this
(setq erc-hide-list '("JOIN" "PART" "QUIT" "NICK"))
;; buffer width
(setq erc-fill-column 140)

;; from http://emacs-fu.blogspot.ca/2009/06/erc-emacs-irc-client.html
(defun erc-start-or-switch ()
  "Connect to ERC, or switch to last active buffer"
  (interactive)
  (if (get-buffer "10.140.40.21:6667") ;; ERC already active?

    (erc-track-switch-buffer 1) ;; yes: switch to last active
    (when (y-or-n-p "Start ERC? ") ;; no: maybe start ERC
      (erc :server "10.140.40.21" :port 6667 :nick "sylnux" :full-name "Sylvain Benner"))))