FaultException was unhandled

[WebMethod]
    public string userDetail(int id, string uname, string pwd, int age, string gender, string place, string country)
    {       
        OleDbConnection con;
        OleDbCommand cmd;
        con = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Users\\Amma\\Documents\\UserDetail.accdb");
        con.Open();
        cmd = new OleDbCommand("insert into login(id,uname,pwd,age,gender,place,country)values(?,?,?,?,?,?,?)", con);
        cmd.Parameters.Add("?", id);
        cmd.Parameters.Add("?",uname);
        cmd.Parameters.Add("?", pwd);
        cmd.Parameters.Add("?", age);
        cmd.Parameters.Add("?", gender);
        cmd.Parameters.Add("?", place);
        cmd.Parameters.Add("?", country);
        cmd.ExecuteNonQuery();
        con.Close();
        return uname;
    }

string name, pwd, gender, place, country;
        int age, id = 0;
        private void BtnRegister_Click(object sender, RoutedEventArgs e)
        {
            ServiceReference1.ServiceSoapClient ws = new ServiceReference1.ServiceSoapClient();
            ws.userDetailCompleted += new EventHandler<userDetailCompletedEventArgs>(ws_userDetailCompletd);

            ws.userDetailAsync(id, name, pwd, age, gender, place, country);
        }
        void ws_userDetailCompletd(object sender,userDetailCompletedEventArgs e)
        {
            id = Convert.ToInt32(textBoxId.Text);
                   pwd = Convert.ToString(textBoxPwd.Text);
                   name = Convert.ToString(textBoxName.Text);
                   age = Convert.ToInt32(textBoxAge.Text);
          
                   if (radioBtnMale.IsChecked == true)
                   {
                       gender = "Male";
                   }
                   else
                       gender = "Female";
                   place = Convert.ToString(textBoxPlace.Text);
                   country = Convert.ToString(textBoxCountry.Text);          
                   MessageBox.Show("successfully Registered");
        }

public Test.ServiceReference1.userDetailResponse EnduserDetail(System.IAsyncResult result) {
                object[] _args = new object[0];
                Test.ServiceReference1.userDetailResponse _result = ((Test.ServiceReference1.userDetailResponse)(base.EndInvoke("userDetail", _args, result)));
                return _result;
            }