Dependend drop-down in PDF form

I thought this would be easy, but the tutorial I'm following is way more complicated than what I'm building, so I'm getting lost.

I'm making a form that has two dropdown lists, and the items in the second one need to depend on what was selected in the first one.

My first dropdown has three selections, and I've written a list of dependent selections formatted like this:

var TopicLink = {

    Planning:[

        ["-","None"],

                ["Border planning"],["border_planning"],

                ["Census issues"],["census_issues"],

                ["Citizens Guide"],["citizens_guide"],

                ["Congestion Management Process"],["congestion_management_process"],

                ["Csstp"],["csstp"],

                ["Delta Region"],["delta_region"],

                ["Economic Development"],["economic_development"],

     ],

     ...

For each of the three items.

I've pasted this into Other Tasks, Javascripts, Document Javascripts (Acrobat X), but when I right click on my second drop-down and pick the Actions Tab (On Focus, Run a Javascript), my JS doesn't appear on the list.

This is my first time touching a PDF form other than to fill one out.  What am I doing wrong?