What is the easiest way to create multiple drop down menus on different html pages that are chained together so you cannot pick the same option twice. Either the second drop down gives you and error or the selection of the first drop down dissapears when going to the second dropdown.

Should I use Javascrip, Ajax, Php with mysql?

Also, if anyone has sample code or a website that implemented this before can you send that over. I looked every where and cannot find any answers.