https://www.vetamerikan.org/App_Themes/AH/assets/js/select.js

1$(document).ready(function () {
2  (function () {
3    var departmanSelectWrapper = $('[data-toggle="departman"]'),
4        doctorSelect = $('[data-toggle="doctors"] select'),
5        selectedDoctor = doctorSelect.val();
6    
7    departmanSelectWrapper.find('select').change(function () {
8      
9      var selectedDepartman = this.value,
10          placeholder = doctorSelect.closest('[data-toggle="doctors"]').attr('data-placeholder');
11      
12      $.get(departmanSelectWrapper.attr('data-ajax-url'), { 'departmentGuidId': selectedDepartman }, function (res) {
13        doctorSelect.children().remove();
14        
15        $(res.data).each(function () {
16          doctorSelect.append('<option value="' + this.DoctorName + '">' + this.DoctorName + '</option>');
17        });
18        
19        if (selectedDoctor !== null) {
20          doctorSelect.val(selectedDoctor).trigger('change');
21          doctorSelect.prepend('<option value="' + placeholder + '">' + placeholder + '</option>');
22        } else {
23          doctorSelect.val(null).trigger('change');
24          doctorSelect.prepend('<option value="' + placeholder + '" selected="selected">' + placeholder + '</option>');
25        }
26        
27      }, 'JSON');
28    });
29    /*	if ($('[data-toggle="departman"] select').val() !== "0") {
30			$('[data-toggle="departman"] select').trigger('change');	
31		}*/
32    setTimeout(function() {
33      if ($('[data-toggle="departman"] select').val() !== "0") {
34        $('[data-toggle="departman"] select').trigger('change');	
35      }
36    });
37    
38  })();
39});