why ajax dose n't work

<script type="text/javascript" >
 
            {
                $(document).ready(function () {
                    alert('hi');
                    $('#CountryAndCity ').change(function () {
 
                        
                        var str = document.getElementById(' CountryAndCity ').value;
                        var str1 = str.split(", ", 1).toString();
                        var str2 = str.split(", ", 2).toString();
 

                        $.ajax({
                            url: '/AccountController/Myaction',
                            data: { countryy: str1, cityy: str2 },
                            cache: false,
                            type: 'GET',
                            success: function (result) {
              
                                $('hidMyModelid_city').val(result);
                                          

                            },

                            error: function (xhr, ajaxOptions, thrownError) {
                       
                                alert(thrownError);
                            },
                        });
 
                    })
                });
            }
 
        </script

public ActionResult MyAction(string countryy, string cityy)
        {
            var result = MyClass.GetIDCity(countryy, cityy);
            return Json(result, JsonRequestBehavior.AllowGet);
            
        }

public static long GetIDCity (string contri, string citi)
        {
            using(SportContext db = new SportContext ())
            {
long Idcontri= db.tbl_country.FirstOrDefault(p => p.country == contri).id;
return db.tbl_city.FirstOrDefault(p => p.id_ country == Idcontri && p.city == citi).id;

            }
           
        }