Looking for an Ajax solution similar to CascadingDropDown but applies to listbox(with multiple selections enabled) instead.

I am looking for an ajax solution similar to CascadingDropDown, but it can be applied to listbox, for example, I have 3 listboxes(Catetory, Producttype, Product) all with multiple selection enabled; so if I select CategoryA and CategoryB in listbox 1(Category), listbox 2(Producttype) will list(populate) all Producttypes related to CategoryA and CategoryB, same rule applies to listbox Producttype and Product.
Since all listboxes are in multiple selection mode, each individual selectiion action should be able to 'remember' last selection item position after the postback(instead of alway starting from the top list of the Listbox).
Any working sample codes are HELPFUL!
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Praveen VenuTechnical Project ManagerCommented:

or try placing them in an updatepanel and postbacking on selectedindexchanged.
RHADMINAuthor Commented:
Hi, Praveenvenu,
http://easylistbox.com/demoRelatedAjax.aspx is not my ideal solution, a perfect solution I found is http://www.codeproject.com/KB/ajax/ListBoxComponent0.6.aspx - an outstanding work!

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
.NET Programming

From novice to tech pro — start learning today.