I have a simple html multi select drop down list:
<select id="transactionType" multiple="multiple" size="10">
<!-- etcetera... -->
New to jQuery was searching the http://jquery.com/ but haven't yet found what I need.
Edit Struts2 users, the selected answer will url encode with  this causes issues in struts2 the fix however is very easy. Simply open jquery.multiSelect.js and search for "" and delete the one instance this is used in a string concatenation. I also am using jQuery 1.4.4 as opposed to the 1.3.2 which came bundled with it and everything works just fine.