Page is not redirecting on other page

protected void reg_report_Click(object sender, EventArgs e)
      {
          LinkButton lnk_regno = (LinkButton)sender;
          string[] CommandArgument = lnk_regno.CommandArgument.Split(',');
          Session["sn_reg_no"] = CommandArgument[0];
          Session["sn_reg_sr_no"] = CommandArgument[1];
          lbl_app.Text = "MOUs SIGN" + " - " + Session["sn_reg_sr_no"].ToString().Trim();

          Imapdf_report.ImageUrl = "get_pdf_app_form.aspx";
          mdl_pdf_report.Show();
          // myframe.Attributes.Add("src", "/vc_office/Temp/" + Session["sn_reg_no"] + "draft_mous" + Session["sn_reg_sr_no"] + ".pdf");
          myframe.Attributes.Add("src", "/Temp/" + Session["sn_reg_no"] + "draft_mous" + Session["sn_reg_sr_no"] + ".pdf");
      }