Is this possible? PHP + Javascript

I have a huge database-driven list of clients with a checkbox next to each one. When I check one of these clients, I'm wanting one of those small javascript boxes to pop up and display the contacts for this client (another database lookup) and allow me to select one via a radio button. I figured I could do this via the checkbox's onclick event, but I'm not completely sure how. How do I bring up the box and display database information within? Any help is GREATLY appreciated. -- Michael Champagne, Software Engineer Capital Institutional Services, Inc. wk: mchampagne@capis.com hm: mchamp@texas.net ****************************************************************** This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction, unless specifically agreed otherwise. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect the views or opinions of Capital Institutional Services, Inc. Capital Institutional Services, Inc. accepts no liability for any errors or omissions arising as a result of transmission. Use of this communication by other than intended recipients is prohibited. ******************************************************************