Object reference not set to an instance of an object error

int index = Convert.ToInt32(e.CommandArgument);
                    var id = ((Label)GridView1.Rows[index].FindControl("lblid")).Text.Trim(); // in this line

                    SqlConnection con = new SqlConnection(connstring);
                    string qry = "Delete from ['ISB VAS Nodes$'] where ID = " + id + "";
                    SqlCommand com = new SqlCommand(qry, con);

                    // open connection
                    con.Open();
                    int numberDeleted = com.ExecuteNonQuery();

                    if (numberDeleted > 0)
                    {
                        Label2.Text = "Deleted";
                        binddata();
                    }
                    else
                    {
                        Label2.Text = "Not Deleted";
                    }

                    // close connection
                    con.Close();
                }
                catch (System.Data.SqlClient.SqlException ex)
                {
                    string msg = "Insert/Update Error:";
                    msg += ex.Message;
                    throw new Exception(msg);

                }

            }