Problem when bind dropdown from jquery in mobile application using json controller

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HTML5

Dear sir
I want to fill dropdown on other dropdown selected index changed event in a mobile application. dropdwon binding code is following.

    <script type="text/javascript">
        function drpbrandChange(id) {
            ShowModels(document.getElementById(id).value);
        }
      function ShowModels(CarSefUrl) {
      var param = { _CarSefUrl: CarSefUrl };
      var data2;
            var _url = "JSON/GetCarModelThroughCarSefUrl_New";
            var _data = param;
            
                var result = null;
                $.ajax({
                    url: _url,
                    cache: false,
                    async: false,
                    data: _data,
                    success: function (data) 
                    {
                        result = data;
                    },
                    dataFilter: function (data) 
                    {
           if (typeof (JSON) != 'undefined' && typeof (JSON.parse) == 'function')
                            if (typeof (JSON.parse(data)) == "object")
                                data2= JSON.parse(data);
                            else
                                data2 = data;
                        else
                            data2 = eval('(' + data + ')');
                    },
                    error: function () 
                    {
                        result = false;
                    }
                });
                
            
            if (data2 != undefined) {
                var items = "<option value=\"\">Select Model...</option>";
                var obj = "#drpModel";
                if (data2 != null) {
                    $.each(data2, function (i, data2) {
items += "<option value=" + data2["ModelName"] + ">" + data2["ModelSefUrl"] + "</option>";
                    });
                    $(obj).html(items);
                }
            }
        }
    </script>

this code is executing successfully in desktop but not working properly in mobile this code is executing some rare case. I test in samsung,blackbarry and endroid mobile phone.

Thanks in advance.