$('.reg_field_available_test_centers_div').hide();
$('#FieldAvailableTestCenters option[value="1500586"]').hide();
$('#FieldSelectMode').change(() =>{
    if ($('#FieldSelectMode').val() == '1500450') {
        $('.reg_field_available_test_centers_div').show();
        $('.form-group.label-floating.field-select.reg_field_available_test_centers_div').css({
            'width': '48%'
        });
        $('.form-group.label-floating.field-select.reg_field_date_of_exam_div').css('width', '48%');
        $('#FieldAvailableTestCenters option[value="1500586"]').hide().prop('selected',false);
    } else {
        $('#FieldAvailableTestCenters').val('1500586').change();
               $('.reg_field_available_test_centers_div').hide();
        $('.form-group.label-floating.field-select.reg_field_date_of_exam_div').css('width', '98%');
    }
});