chain menu but the menu should be multiple select menu/list

[searain]

http://www.dynamicdrive.com/dynamicindex1/chainedmenu/index.htm this javascript, the menu is single select menu.

I am looking for codes to be able to do the same thing with multiple select menu/list.

PHP codes or javascripts codes are both fine.

1) javascript + php approach: Prefer to be javascripts codes to display the chain menu. I can use the php to get the all three levels menu data from the database, and assign these values to the javascript.

2) php codes only: Or use the pure php codes (the problem is if just using php codes then I have to submit the form to the server every time, when top level menu select changes to create new menu.)

Thanks!