https://obust.ru/themes/theme1001/js/tools/vatManagement.js

1$(document).ready(function(){
2	vat_number();
3	vat_number_ajax();
4
5	$(document).on('input', '#company, #company_invoice', function(){
6		vat_number();
7	});
8});
9
10function vat_number()
11{
12	if (($('#company').length) && ($('#company').val() != ''))
13		$('#vat_number, #vat_number_block').show();
14	else
15		$('#vat_number, #vat_number_block').hide();
16
17	if (($('#company_invoice').length) && ($('#company_invoice').val() != ''))
18		$('#vat_number_block_invoice').show();
19	else
20		$('#vat_number_block_invoice').hide();
21}
22
23function vat_number_ajax()
24{
25	$(document).on('change', '#id_country', function()
26	{
27		if (typeof vatnumber_ajax_call !== 'undefined' && vatnumber_ajax_call)
28			$.ajax({
29				type: 'POST',
30				headers: {"cache-control": "no-cache"},
31				url: baseDir + 'modules/vatnumber/ajax.php?id_country=' + parseInt($(this).val()) + '&rand=' + new Date().getTime(),
32				success: function(isApplicable){
33					if(isApplicable == "1")
34					{
35						$('#vat_area').show();
36						$('#vat_number').show();
37					}
38					else
39						$('#vat_area').hide();
40				}
41			});
42	});
43}