That's done in the "options" data structure: The element before the ':' (e.g. "One") is the value that gets selected in Dropdown1, and the elements after ':' (e.g. " [ "one.1", "one.2", "one.3" ]" are the option you want to make available for selection in Dropdown2.
What you want to do is a bit more complex, and would require a slightly different approach.
To hide dropdown2 (or set it to readonly), you would add more code to the custom validation script. You can for example use the following (just set the values in Dropdown3 instead of Dropdown2 - I also renamed the options data structure so that you can also have one called transactionOptions):
var litigationOptions = {
"One" : [ "one.1", "one.2", "one.3" ],
"Two" : [ "two.1", "two.2", "two.3" ],
"Three" : [ "three.1", "three.2", "three.3" ],
};
if (event.value != " ") {
this.getField("Dropdown2").readonly = true;
this.getField("Dropdown3").setItems(litigationOptions[event.value]);
}
else {
this.getField("Dropdown2").readonly = false;
this.getField("Dropdown3").clearItems();
}
Do something very similar with Dropdown2, just set Dropdown1 to readonly and use a different set of options for Dropdown3.
Karl Heinz Kremer
PDF Acrobatics Without a Net
PDF Software Development, Training and More...
http://www.khkonsulting.com