Checking Select Option Value Without Form Submital

I am allowing a user to selected a date to schedule an event and it
seems like the best way to do this is with drop down menus for Year,
month, date. However I would like to make it so when you choose a year
and a month the appropriate days for that month show (i.e. 28 days if
you chose February 2006). I can easily do this with a loop if I can
find out what month the user has selected, but I can't seem to find a
way to get that value. Is there a simple javascript solution to this
problem?
Received on Tue Feb 7 21:35:43 2006