I have some problem in dynamic html generation in asp.net c#

public void call()
        {
            for (int x = 0; x < 5; x++)
            {

                for (int times = 0; times < 20; times++)
                {
                    string str = "<table border=" + " 2=" + "><tr>";
                    // string str1 = "<table border=" + " 2=" + " width=" + " 400=" + "><tr>";
                    var generated = 0;
                    var rand = new Random(DateTime.Now.Millisecond);
                    for (var i = 0; i < Rows; i++)
                    {
                        Card[i] = new int[Cols];
                    }

                    while (generated < (Cols * Rows))
                    {
                        var num = rand.Next(1, 90);

                        if (!Contains(num))
                        {
                            var row = generated / Cols;
                            var currentCol = generated - (row * 5);

                            if (!Card[row].Any(c => c > 0 && c / 10 == (num / 10)))
                            {
                                generated++;
                                Card[row][currentCol] = num;
                            }
                        }
                    }

                    for (var i = 0; i < Rows; i++)
                    {
                        Array.Sort(Card[i]);
                    }

                    for (var i = 0; i < Cols; i++)
                    {
                        SortNumber(i, 1, 2);
                        SortNumber(i, 0, 1);
                        SortNumber(i, 0, 2);
                    }

                    for (var row = 0; row < Rows; row++)
                    {
                        //str = str + "<tr>";
                        for (var i = 0; i < 9; i++)
                        {

                            bool found = false;
                            for (var col = 0; col < Cols; col++)
                            {
                                if (Card[row][col] / 10 == i)
                                {
                                    found = true;

                                    sql = "select * from songsDB where id = '" + Card[row][col] + "' ";

                                    ad = new SqlDataAdapter(sql, con);

                                    DataTable dt = new DataTable();
                                    ad.Fill(dt);


                                    DataRow row1 = dt.Rows[0];
                                    data = row1["id"].ToString();

                                    data = data + "   " + row1["song"].ToString();
                                    // var d = row1["song"];
                                    // table.AddCell(data);

                                    str = str + "<td width=" + ">" + data + "</td>";

                                    break;
                                }
                            }

                            if (!found)
                            {
                                str = str + "<td> NULL </td>";
                                // table.AddCell("NULL");

                            }

                        }
                        str = str + "</tr>";

                    }
                    str = str + "</tr></table>";
  divTable.InnerHtml = str;

                }

            }