EDIT: Sorry, I'm tired and not thinking at 100%. It depends on why you can't work that day.
My opinion: If it's really all that important, ask them to take the day off and they'll understand. Otherwise, you'll have to decide if this event is more important that your attendance or even your job itself.
Post edited at 8:22 pm on Oct. 28, 2008 by xxKayeKayexx
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I am not one who was born in the possession of knowledge; I am one who
is fond of antiquity, and earnest in seeking it there.-Confucius