Embedded Checkboxes under Checkboxes?

Question

In a PDF form I'm creating, there are a number of checkboxes.  So far, so good.  Once you click a checkbox, I want to have some "sub" boxes open up to check. Similar to this:
I own a pet.
It's a cat.
It's a dog.
I don't want the person responding to be able to click "It's a cat" before clicking "I own a pet." Only after clicking "I own a pet" should they be able to click one of the two options.
Make sense?  I think I do this with a list box, but not sure.  I've checked the Help feature, but couldn't find the information I need.  Nowhere does it tell you how to set up a list box or what it would look like when you're done.
Help?

Answer 1

A list box does not work that way. You can individual check boxes, but you have to include a JavaScript in the mouse p event of the first one. The script would activate the dependant check boxes if the first one is selected and disable them if not. It would look something like:
// Mouse Up script for check box
(function () {
    // Get the value of this check box
    var v = event.target.value;
    // Get references to the other check boxes
    var f1 = getField("cbDog");
    var f2 = getfield("cbCat");
    // Reset the other check boxes
    f1.value = "Off";
    f2.value = "Off";
    // If this check box is selected, activate the other check boxes
    if (v !== "Off") {
        f1.display = display.visible;
        f2.display = display.visible;
    } else {  // deactivate the other check boxes
        f1.display = display.hidden;
        f2.display = display.hidden;
If you don't want to hide the field but just make it so the user cannot select them, set the "readonly" property instead. For example:
f1.readonly = true;
f2.readonly = true;
Edited to correct a typo.