https://trtfn.com/wp-content/themes/scalia/js/combobox.js?ver=6.0.16

1(function($) {
2	$.fn.combobox = function() {
3		$(this).each(function() {
4			var $el = $(this);
5			$el.insertBefore($el.parent('.combobox-wrapper'));
6			$el.next('.combobox-wrapper').remove();
7			$el.css({
8				'opacity': 0,
9				'position': 'absolute',
10				'left': 0,
11				'right': 0,
12				'top': 0,
13				'bottom': 0
14			});
15			var $comboWrap = $('<span class="combobox-wrapper" />').insertAfter($el);
16			var $text = $('<span class="combobox-text" />').appendTo($comboWrap);
17			var $button = $('<span class="combobox-button" />').appendTo($comboWrap);
18			$el.appendTo($comboWrap);
19			$el.change(function() {
20				$text.text($('option:selected', $el).text());
21			});
22			$text.text($('option:selected', $el).text());
23			$el.comboWrap = $comboWrap;
24		});
25	}
26})(jQuery);