Jquery AutoComplete in asp.net using Webmethod

Here is the Script Code

function UserNameAutoComplete() { 

    $("#UserName").autocomplete

        ({

            source: function (request, response) {

                $.ajax

                    ({

                        url: "GSIRRegionConfigFSSCUserLsPg.aspx/GetADUsers",

                        data: "{ 'strADUser' : '" + $("#UserName").val() + "'}",

                        dataType: "json",

                        type: "POST",

                        async: true,

                        contentType: "application/json; charset=utf-8",

                        dataFilter: function (data) { return data; },

                        success: function (data) {

                            if (data.d.length == 0) {

                                $("#UserName").val('');

                            }

                            else {

                                $("#UserName").val();

                            }

                            response($.map(data.d, function (item) {

                                return {

                                    value: item

                                }

                            }));

                        },

                        failure: function (response) {

                            alert(response.d);

                        },

                        error: function (XMLHttpRequest, textStatus, errorThrown) {

                            alert(textStatus);

                        }

                    });

            },

            select: function (event, ui) {

                varusrsplit = ui.item.value.split(",");

                document.getElementById('UserName').value = '';

                document.getElementById('UserName').value = varusrsplit[0];

                document.getElementById('UserID').value = varusrsplit[1];

                ui.item.value = ui.item.value.split(",")[0];

            },

            minLength: 3

        });

}

Here is the WebMethod

[WebMethod]

    public static List<string> GetADUsers(string strADUser)

    {

        string AutoCmpltVal = string.Empty;

        List<string> objList = new List<string>();

        string query = string.Format("Select distinct EmployeeName,UserAccount from AdmADUserMasterDetails where EmployeeName LIKE '%{0}%'", strADUser);

        using (SqlConnection con = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["SQLConnectionString"]))

        {

            SqlCommand cmd = new SqlCommand(query, con);

            SqlDataReader dr;

            con.Open();

            dr = cmd.ExecuteReader();

            while (dr.Read())

            {

                AutoCmpltVal = (string)dr["EmployeeName"] + "," + (string)dr["UserAccount"];

                objList.Add(AutoCmpltVal);

            }

            return objList;

        }

    }