jQuery show hide基于序列化哈希的选择菜单

I am trying to get select menus show hide by using ajax and serialised hashes. I had this system working last night but I changed the #selector from a form to a div and suddenly its stopped running. I had to broaden the form for additional data on post and did not want to serialise all the data at once for this as it would be additional strain on the system. I am trying to get select menus show hide by us