Quadruple Dynamically-Linked Listboxes

Can someone provide me with the code necessary to have 4 listboxes that are dependent upon one-another? In other words, the selection in #1 populates #2, #2 populates #3, and #3 populates #4.

I've gotten as far has having 3 work successfully, and I thought adding a forth would be fairly straight-foward, but so far I haven't been able to get it work correctly.

Any help you can provide is greatly appreciated.

Thanks!

There are several threads on this topic (with links to existing tools) already.

dhouston, I've searched the site numerous times over, on all of the keywords, only to not have any results returned to me.

I did a search on "select box" and turned up several possible hits, of which the most obvious was http://forums.devarticles.com/t8730/s.html&highlight=select+box. There are a couple of links to dynamic select-box scripts there that may help you out (even if you don't switch to one of the scripts, looking at how they work might give you a hint).