ASP.NET

protected void Button2_Click(object sender, EventArgs e)
    {
        OleDbDataReader dr = null;
        string str = "Select * From ProductSpecification";
        OleDbCommand cmd = new OleDbCommand(str, conn);
        conn.Open();
        dr = cmd.ExecuteReader();
        for (int i = 1; i < dr.VisibleFieldCount; i++)
        {
            while (dr.Read())
            {
                string s=dr["Specification"].ToString();
                TextBox txtctrl=new TextBox();
                txtctrl=(TextBox)Panel2.FindControl("txt" + s);
                    string s1 = txtctrl.Text;
                    string s2 = "Update ProductSpecification Set(Value='" + s1 + "')";
                    cmd = new OleDbCommand(s2, conn);
                    cmd.ExecuteNonQuery();
                
            }
        }
        conn.Close();
    }