nested Combobox

I have a form where I wanted nest two combobox:
I proceeded as follows (file attachment), but I get the following error:

TypeError: this.optionsArr[a] is undefined.

Thank you for your help
form.rar (311 KB)

First of all use right file names:

replace with

Or delete this line at all, because it dublicates.
Second: you need to specify combotype comboType: “checkbox” in form data.
And the third thing is very important: you need to use callback to check the item
combo3.loadXML(“xml/combo_0_2.xml”, function(){

is that instead of this:

combo3.loadXML("xml/combo_0_2.xml", function(){

I can do this, to load the items from the database

combo3.load("some-file.php", function(){

Thank you for your support

Yes, it just depends on your method of loading item :slight_smile:

Thank you!

I’ll try and tell you after