Mt-plugin-cf-twodimselect is a project mainly written in Perl, it's free.
A Movable Type Pro plugin that adds support for a two-dimensional pull down menu; select an item in one menu to reveal a second.
This plugin provides a new custom field type to Movable Type Pro users. This new field type, called a "two dimensional select" allows one to have a pull down menu, which when a selection is made, reveals a second pull down menu to further narrow down the user's choice. This is perfect for managing LARGE pull down menus for which the menu's content is easily categorized, e.g. states within regions, cities within states, etc.
Create a new Custom Field.
Select "Drop Down Menu (2-Dimensional)" as the field's type.
In the Options text area that appears enter in data according to the following structure:
{
"California" => [ "LA","San Francisco","San Diego" ],
"Texas" => [ "Dallas","Houston","Austin" ],
"Lousiana" => [ "New Orleans","Sliddel","Baton Rougue" ],
}For those familiar with Perl, you will recognize this is a simple hash.
Syntax is important here, so pay attention to placement of commas, and make sure all square and curly brackets are opened and closed properly.
To install this plugin follow the instructions found here:
http://tinyurl.com/easy-plugin-install
This plugin is licensed under the same terms as Perl itself.