Timer callback function does not fire

Dear All,
 hope someone can help me with this ... i have simple enough code moslty
taken from TestTimer class. I just want to create a timer that fires a
callback function. I have tried initializing the Timer with a (Callback
function f, user_data) in which case f should be called when
timer.schedule_now() is called in initalize().
i have put click_chatter in the initialize() function and the callback but
only the chatter from initialize comes up in dmesg.

If I try to initialize the timer with Timer(Element *) on a call to
timer.schedule_now() the element class's run_timer() should be called but
no chatter shows up in dmesg.

plz help i have spent some days on this problem and seemed to have gone
through most code files for the timer class and TimerTest but to no avail!

thank u in advance
momina