I am creating an admin backend for a site.
This admin backend will add instructors.
I need to have the ability to assign the instructors to several categories. So far easY? Multiple select field.

Here is where i am stuck.
I need a nice way of adding new categories on the fly without refreshing entire page.
Anyone know of any ajax, jqueryui or tutorial on how to accomplish this using PHP/MYSQL values that populate the categories field?