Getting 2 Selection List Boxes Working Together

Here is my situation, I have an ASP page with 2 list boxes. The first list box displays people that are available to be selected. The other list box shows the people who have been selected. This makes it easy to see who has been selected and who has not been selected since if you are in one list box you will not be in the other.

I know how to write the SQL to get the data for each list box but my problem is getting this to work without having to reload the whole page (I thought I could just re-run each list boxes' SQL and display the results instead of having to load the page again).

Write now I was thinking each list box would have an OnClick or OnChange JavaScript event. I would then have 1 table with all People in it and a second table of people who were selected. When the user clicked on the list box of available people (not selected) I need to run an ASP insert script and then requery both list boxes to pick up the change. In the case a user was removed from the selected list box, I need to run a Delete ASP script.

My problem is that I can do this if I reload the page every time a person is selected from a list but there has to be a way this can be done without reloading the page. Do you have any ideas or suggestions?