I m dynamicaly adding row in ASP.Net table in my web project but when i am inserting data in first row and i want to add another row then first row data is lost......please help me

public partial class Code_User_DMSdataclass : System.Web.UI.Page
{
    private int numOfRows = 1;
    SqlCommand cmd = null;
    SqlConnection objSqlConnection1 = null;
    Dataconnection connection = new Dataconnection();
    priviligesChecking priviliges = new priviligesChecking();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            ViewState["RowsCount"] = numOfRows + 1;
            GenerateTable(numOfRows);
            
        }
        System.Web.UI.WebControls.Button btn = (System.Web.UI.WebControls.Button)Panel2.FindControl("btn_addindex");
        if (btn == null)
        {
            if (ViewState["RowsCount"] != null)
            {
                numOfRows = Convert.ToInt32(ViewState["RowsCount"].ToString());
                GenerateTable(--numOfRows);
            }
        }
        
    }
   
    protected void btn_addindex_Click(object sender, EventArgs e)
    {

        if (ViewState["RowsCount"] != null)
        {
            numOfRows = Convert.ToInt32(ViewState["RowsCount"].ToString());
            GenerateTable(numOfRows);
        }
    }
    private void SetPreviousData(int rowsCount, int colsCount)
    {
        ArrayList name = new ArrayList();
        ArrayList discription = new ArrayList();
        ArrayList type = new ArrayList();
        Table table = (Table)Panel1.FindControl("table3");
        if (table != null)
        {
            for (int i = 0; i < rowsCount; i++)
            {
                for (int j = 0; j < colsCount; j++)
                {
                    if (j == 2)
                    {
                        DropDownList Db =(DropDownList)table.Rows[i].Cells[j].FindControl("TextBoxRow_" + i + "Col_" + j);
                        Db.Text =Request.Form["TextBoxRow_" + i + "Col_" + j];
                        string d_type = Db.Text;
                        type.Add(d_type);
                    }
                    //Extracting the Dynamic Controls from the Table
                    if (j == 1)
                    {
                        System.Web.UI.WebControls.TextBox tb = (System.Web.UI.WebControls.TextBox)table.Rows[i].Cells[j].FindControl("TextBoxRow_" + i + "Col_" + j);

                        //Use Request objects for getting the previous data of the dynamic textbox
                        tb.Text =Request.Form["TextBoxRow_" + i + "Col_" + j];
                        string d_d = tb.Text;
                        discription.Add(d_d);
                    }
                    if (j == 0)
                    {
                        System.Web.UI.WebControls.TextBox tb1 = (System.Web.UI.WebControls.TextBox)table.Rows[i].Cells[j].FindControl("TextBoxRow_" + i + "Col_" + j);
                        
                        //Use Request objects for getting the previous data of the dynamic textbox
                        tb1.Text = Request.Form["TextBoxRow_" + i + "Col_" + j];
                        string discriptor = tb1.Text;
                        name.Add(tb1.Text);
                    }

                }
            }

        }
        ViewState["Name"] = name;
        ViewState["Descriptor"] = discription;
        ViewState["Type"] = type;
    }
    private void GenerateTable(int rowsCount)
    {
        objSqlConnection1 = connection.getConnection();
        objSqlConnection1.Open();
        //Creat the Table and Add it to the Page
        Table table = new Table();
        table.ID = "table3";
        Panel1.Controls.Add(table);
        //The number of Columns to be generated
        const int colsCount = 3;//You can changed the value of 3 based on you requirements
        // Now iterate through the table and add your controls
        for (int i = 0; i < rowsCount; i++)
        {
            TableRow row = new TableRow();
            for (int j = 0; j < colsCount; j++)
            {
                TableCell cell = new TableCell();
                System.Web.UI.WebControls.TextBox tb = new System.Web.UI.WebControls.TextBox();
                DropDownList dl = new DropDownList();
                // Set a unique ID for each TextBox added
                // Add the control to the TableCell
                if (j == 2)
                {
                    
                    string query1 = "select * from Tbl_Datatype";
                    cmd = new SqlCommand(query1, objSqlConnection1);
                    SqlDataReader dr1;
                    dr1 = cmd.ExecuteReader();
                    dl.Items.Add(new ListItem("Select One...", "-1"));
                    int Dt_id1;
                    string Dt_name;
                    //String g_name;
                    //int p_type_id;

                    while (dr1.Read())
                    {
                        Dt_id1 = dr1.GetInt32(0);
                        Dt_name = dr1.GetString(1).ToString();
                        dl.Items.Add(new ListItem(Dt_name, Dt_id1.ToString()));
                        //dbodescriptor2.Items.Add(new ListItem(Dt_name, Dt_id1.ToString()));
                        //dbodescriptor3.Items.Add(new ListItem(Dt_name, Dt_id1.ToString()));
                    }
                    dr1.Close();
                    dl.ID = "TextBoxRow_" + i + "Col_" + j;
                    dl.CausesValidation = false;
                    dl.Width = new Unit("230");
                    cell.Controls.Add(dl);
                    row.Cells.Add(cell);
                }
                // Add the TableCell to the TableRow
                else
                {
                    tb.ID = "TextBoxRow_" + i + "Col_" + j;
                    tb.CausesValidation = false;
                    tb.Width = new Unit("210");
                    cell.Controls.Add(tb);
                    row.Cells.Add(cell);
                }
            }
            table.Rows.Add(row);
        }
        SetPreviousData(rowsCount, colsCount);
        rowsCount++;
        ViewState["RowsCount"] = rowsCount;
    }
}