Adding controls dynamically

I have one table control "table1"
And added controls to it in click event of one button as :
protected void Button2_Click(object sender, EventArgs e)
{
        TableRow row;
        TableCell cell;
        for (int i = 0; i < 3; ++i)
        {
            TextBox txt = new TextBox();
            txt.Text = i.ToString();
            row = new TableRow();
            cell = new TableCell();
            cell.Controls.Add(txt);
            row ...