1) submit the page and refresh the list content of the second dropdown box use server side tech. (asp/jsp/isapi/cgi......)
2) build the tree into javascript, in onchange event of the first dropdown box, using DOM/script to modify the items of the second one. If the number of items are not too much, this is the fastest way.
3) In onchange event of the first dropdown box, generate a xmlhttprequest object and fill in the value, and on the server side, return the list, then using DOM/script to modify the list in dropdown box B. This one require MSXML on the client side, good for intranet applications.
2) build the tree into javascript, in onchange event of the first dropdown box, using DOM/script to modify the items of the second one. If the number of items are not too much, this is the fastest way.
3) In onchange event of the first dropdown box, generate a xmlhttprequest object and fill in the value, and on the server side, return the list, then using DOM/script to modify the list in dropdown box B. This one require MSXML on the client side, good for intranet applications.