AJAX Enabled Selector TagLibrary

I am in need of creating a set of AJAX enabled Tags (within a TagLibrary) for use on my web application.   Each tag will be independent (not nested), with the ability to communicate with eachother.  I plan on doing this via the ID attribute and adding the tags to the pageContext.

Each tag will be a drop down menu (select tag).  The first tag is a list of Building numbers (i.e. 100, 101, 102, etc.).  The second tag is a list of Room numbers (i.e. 1A, 1B, 2A, etc.).  

The reason AJAX comes into play here is that the list of Room numbers is dependent upon which Building number has been selected.  

Each time the "selectedIndexChanged" event fires for the Building drop down, I need to be able to execute a method that will re-bind the Room drop down list.  

500 PTS.

Thanks in Advance.