onchange is a JavaScript mechanism that triggers on the client side long after the JSP (including JSTL tags) has been executed on the server in order to format and send the generated HTML page to the browser.
To communicate back with the server, you'll need to submit the form -- preferably to a
servlet: I strongly discourage performing database actions in the presentation layer, especially within a JSP.
If you'd rather not refresh the whole page, you might investigate making the request via Ajax.
[ May 15, 2006: Message edited by: Bear Bibeault ]