dear blah
i am writing this letter to inform you of my intention to give notice from --/--/2007. This will make my last working day --/--/2007
I would like to take this opportunity to thank you for the support you and the team have gven me over the last blah amount of time, and let you know i have enjoyed working here. (even if you havent particularly enjoyed it, you never know who you might run into on your career path later, so there is no point in whinging)