autochecking for new messages/articles while inside group

["Bryan K. Walton" <walton@mailbag.com>]

Forgive me if this issue has been addressed before.  I am new to Gnus
and recently subscribed to the list.

I am running Gnus inside Emacs 21.1.  I am using Gnus to do imap to my
mailserver.  I have that successfully working for the most part.  What I
am interested in doing is having Gnus automatically check for new
messages while the imap session is running and I am inside the group.
After searching the web for a while, I stumbled across the following but
it still isn't auto-checking:

-- snip --

(defvar check-gnus-timer nil)

(defvar check-gnus-interval 60
  "* Seconds between gnus-checks.")
(defvar check-gnus-level 1
  "* Gnus level to check.")
(defun check-gnus ()  
  ""
  (interactive)
  (and check-gnus-timer (cancel-timer check-gnus-timer))
  (setq check-gnus-timer
        (run-at-time nil check-gnus-interval
        'check-gnus-event-handler)))
(defun check-gnus-event-handler ()
 (message (concat (current-time-string) "- check-gnus - checking
mail..."))
; save current state here for comparison after check?
(gnus-group-get-new-news check-gnus-level))

-- snip

So far, the only way I can get Gnus to see new messages is to exit the
group and then tell Gnus to "get newly arrived articles".

Is there a way to automate this?

Thanks!
Bryan Walton