Print Crystal Report multiple times based on user input using C# in ASP.Net

Here i found a code, on crystal report fetch data which want to print and add parameter (Pageno and Totalpage) and use below code

        protected void btnprnt_Click(object sender, EventArgs e)
        {
            if (Convert.ToInt32(txtqty.Text) > 0)
            {
                try
                {
                    con.Open();
                    SqlCommand cmd = new SqlCommand("sp_Importlabelprint", con);
                    cmd.CommandType = CommandType.StoredProcedure;

                    SqlDataAdapter da = new SqlDataAdapter(cmd);
                    DataSet ds = new DataSet();
                    da.Fill(ds);
                    //SqlDataAdapter adp = new SqlDataAdapter("select prdno,orderno,Codeitem,prdqty from probale", con);
                    //DataSet ds = new DataSet();
                    //adp.Fill(ds);

                    for (int i = 0; i < Convert.ToInt32(txtqty.Text); i++)
                    {
                        ReportDocument rpt = new ReportDocument();
                        rpt.FileName = Server.MapPath("~/Importlbprint.rpt");
                        rpt.SetDataSource(ds.Tables["Table"]); //DS is Dataset which you want to print

                        rpt.SetParameterValue("PageNo", i + 1);
                        rpt.SetParameterValue("TotalPage", Convert.ToInt32(txtqty.Text));
                        rpt.PrintToPrinter(1, false, 1, 1);
                    }
                    string url = "/lbimportprints.aspx?noc=" + txtqty.Text;
                    Page.ClientScript.RegisterStartupScript(
                    this.GetType(), "OpenWindow", "window.open('"+url+"','_newtab');", true);
                }
                catch (Exception ex) { }
            }
        }
    }