How to make the contents of the second
<select> depend on the selection of the element of the first
<select> . Those. until the user selects an item in the first (namely, it is on
<option>---</option> ), then in the second there is a disabled attribute. When it is already selected, the attribute is removed and a menu is created with items dependent on the choice of an item in the first menu.
Tell me, please, how to implement such a thing, or can there be ready-made plugins?