JavaScript-HTML: Create ComboBox with non-selectable items

Question

I would like to create a ComboBox like you can see in the following image

The Combo/Menu/List should allow some items to be bold (Main Categories), and to have "sub-categories" under each main category. The bold items should not be clickeable or selectable (I guess these items should have value="") ?

Thanks

Answer 1

You want to look into optgroup tag

Answer 2

Well, that isn't a combobox (there is no free text component), so all you need to do is include some optgroup elements.

Answer 3

For the formatting, you might want to try jListbox: jquery plugin: