Web Custom Control - Get Calling control

Hi. I created 4 drop downlist controls as web custom controls, which I would either like to use seperately, or working together like a hierarchy (dependant on each other). The problem is, I need to communicate with the calling control (the web page where I dragged these controls on). When the dropdownlists are used seperately, they should return all items on a table, but when they are used together, the child dropdownlist should only return items from the table based on the selection of the parent dropdownlist just above it. Can anyone please help? Thanks.You should post this in theBuilding Controls Forum. You would get better results.
Regards

I posted it there right after this post (new to the site), but I haven' t had a response yet. Hope there is someone that can help.

Yes sure, but don't forget time difference. Where are you living? There are experts in each forum, so those who heavily work with custom controls and stuff like that usually hang out at that forum, others hang out in the forums they have expertise in.
regards