[xmonad] why dose not my urgency hook work?

[Changying Li]

hi. I want to let something flash when the hidden desktop or window
demands my attention. so I tried urgency hook. But it didnt work. its my
configure:

statusBarCmd= "dzen2 -bg '#1a1a1a' -fg '#777777' -h 16 -w 600 -sa c -e '' -fn '-*-courier-*-r-normal-*-*-120-*-*-*-*-iso8859-*' -ta l"
main = do din <- spawnPipe statusBarCmd
          xmonad $ withUrgencyHook dzenUrgencyHook { args = ["-bg", "yellow", "-xs", "1"] } 
                 $ defaults {
                       logHook = dynamicLogWithPP $ dzenPP { ppOutput = hPutStrLn din }
                     }

and when I use dynamicLogDzen directy , the dzen showed nothing, but
when I use dzenPP it worked.

btw, I'm using archlinux and xmonad 0.7
-- 

Thanks & Regards

Changying Li