Can anyone offer any advice on this script

I've been using Jasons Sate Input Calendar on my website for a number of years and it is really good and works really well however there is one minor modification I would like to make

The Day and Month Options have a drop down so you can change without using the calendar, the Year doesn't. I would like to add this to the year option but can't figure out how to add a drop down.

It would help visitors to this page as I had a user looking to change the date to 2013.

The page I'm looking at is www.stroudskittles.co.uk/rearranged.html

Any help very much appreciated

Many Thanks