Show Crystal report reportviewer from asp.net server side button click using ScriptManager.RegisterStartupScript inside update panel

Method 1: 
 public void showReportModified(string pageUrl, string param, System.Type cType, Page oPage, Control ctrl)
        {
            ScriptManager.RegisterStartupScript(ctrl, typeof(string), "redirect", "window.open('" + pageUrl + param + "');", true);
        }
Method 2:
      public void showReport(string pageUrl, string param, System.Type cType, Page oPage)
        {
            string url = ResolveClientUrl(pageUrl) + param;

            //for (int i = 0; i < param.Length; i++)
            //{
            //    url += pageUrl + Server.UrlEncode(param[i]);
            //}
            ClientScriptManager crScript = oPage.ClientScript;
            //Type cType = this.GetType();
            string script = @"<script language=javascript>window.open('" + url + "')</script>";
            if (!crScript.IsClientScriptBlockRegistered(cType, "ViewReport"))
                crScript.RegisterClientScriptBlock(cType, "ViewReport", script);
        }
Method 2:
        public void showReport2(string pageUrl, string param, System.Type cType, Page oPage)
        {
            string url = ResolveClientUrl(pageUrl) + param;

            //for (int i = 0; i < param.Length; i++)
            //{
            //    url += pageUrl + Server.UrlEncode(param[i]);
            //}
            ClientScriptManager crScript = oPage.ClientScript;
            //Type cType = this.GetType();
            string script = @"<script language=javascript>window.open('" + url + "')</script>";
            if (!crScript.IsClientScriptBlockRegistered(cType, "ViewReport2"))
                crScript.RegisterClientScriptBlock(cType, "ViewReport2", script);
        }

Method 1 Example: 
 string URL = ResolveUrl("~/Report/Viewers/ReportViewer.aspx?ReportType=RequisitionNumberReport&RequisitionNumber=" + reqNo + "");
                //ScriptManager.RegisterStartupScript(UpdatePanel1, UpdatePanel1.GetType(), "newWindow", URL, true);
                showReportModified(URL, "", this.GetType(), this.Page, UpdatePanel1);