http://web.mt-systems.jp/tech/cakephp/jqueryajax2
http://d.hatena.ne.jp/deeeki/20090313/getjsonselect
http://www.okushin.co.jp/kodanuki_note/2011/03/post-8.html
http://www.openspc2.org/reibun/javascript/form_selectmenu/015/
http://blog.xao.jp/blog/cakephp/one-of-the-simple-way-for-using-ajax-in-cakephp/