public string HelloWorld(string BookingID, string Name, string Email, string Contact_No, string Event_Name, string responceURL)
    {
        //Session["ID"] = entid.ToString();
        DataTable dt = TransactionBOL.Check_EventTransaction(BookingID);

        if (dt.Rows.Count == 0)
        {
            decimal  TotalAmount   = Convert.ToDecimal("1000");
            DateTime DateofBooking = DateTime.Now.Date;
            string   ISDCode       = "91";
            // String BookingID = EVENT00000; //for the FirstTime//
            TransactionRecord tr = new TransactionRecord();
            tr.EvtBookingID   = GTICKBOL.EventBooking_Max();
            tr.EvtTotalAmount = Convert.ToDecimal(TotalAmount);
            string evtbookingid = MaxBookingId(tr.EvtBookingID.ToString());
            tr.EvtBookingID = evtbookingid;
            int enrty = GTICKBOL.EventBooking_Details(Event_Name + BookingID, Name, Event_Name, Contact_No, Event_Name, responceURL, TotalAmount, DateofBooking, false, "", tr.EvtBookingID.ToString());
            //********Payment GateWay Flow******//
            #region Payment GateWay Flow
            Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write(tr.EvtBookingID.ToString() + "Sending to HDFC Payment Gateway");
            string trackid, amount;
            string URL = "";
            trackid = tr.EvtBookingID.ToString();
            //Session["trackid"] = trackid;
            amount = TotalAmount.ToString();
            String ErrorUrl    = KoDTicketingIPAddress + "EventTransaction/HDFC/Error.aspx";
            String ResponseUrl = KoDTicketingIPAddress + "EventTransaction/HDFC/ReturnReceipt.aspx";

            string qrystr = "id=" + HDFCTransPortalID + "&password="******"&action=1&langid=USA&currencycode=356&amt=" + amount
                            + "&responseURL=" + Server.UrlEncode(ResponseUrl) + "&errorURL=" + Server.UrlEncode(ErrorUrl)
                            + "&trackid=" + trackid
                            + "&udf1=TicketBooking&udf2=" + "".Trim()
                            + "&udf3=" + Server.UrlEncode(ISDCode.ToString().TrimStart('+') + "") + "&udf4=" + Server.UrlEncode("".Trim()) + "&udf5=" + tr.BookingID.ToString();

            Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write("Preparing for HDFC Payment..." + qrystr);

            System.IO.StreamWriter requestWriter = null;
            Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write("Redirecting for HDFC Payment..." + HDFCTransUrl);
            System.Net.HttpWebRequest objRequest = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(HDFCTransUrl);       //create a SSL connection object server-to-server
            objRequest.Method          = "POST";
            objRequest.ContentLength   = qrystr.Length;
            objRequest.ContentType     = "application/x-www-form-urlencoded";
            objRequest.CookieContainer = new System.Net.CookieContainer();

            try
            {
                Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write("Processing request for HDFC Payment...");
                requestWriter = new System.IO.StreamWriter(objRequest.GetRequestStream());      // here the request is sent to payment gateway
                requestWriter.Write(qrystr);
            }
            catch (Exception ex)
            {
                Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write("Excetion while processing HDFC payment: " + trackid + ex.Message);
            }

            if (requestWriter != null)
            {
                requestWriter.Close();
            }

            Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write("Review validation response from HDFC Payment Gateway...");
            System.Net.HttpWebResponse objResponse = (System.Net.HttpWebResponse)objRequest.GetResponse();

            using (System.IO.StreamReader sr =
                       new System.IO.StreamReader(objResponse.GetResponseStream()))
            {
                String NSDLval = sr.ReadToEnd();
                Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write("Response: " + NSDLval);
                if (NSDLval.Contains("Invalid User Defined Field"))
                {
                    return("The information submitted contains some invalid character, please avoid using [+,-,#] etc.");
                }

                //Writefile_new("\n***************Initial Response********************", Server.MapPath("~"));
                //Writefile_new("\n\nDateTime:" + DateTime.Now.ToString("dd/MM/yy HH:mm:ss") + " Reference No:" + trackId + "Request XML:" + NSDLval, Server.MapPath("~"));
                if (NSDLval.IndexOf("http") == -1)
                {
                    return("Payment cannot be processed with information provided.");
                }

                // gb.HDFCLog(transid.ToString(), "", trackId, "***Initial Response*** : " + NSDLval);
                string strPmtId  = NSDLval.Substring(0, NSDLval.IndexOf(":http"));      // Merchant MUST map (update) the Payment ID received with the merchant Track Id in his database at this place.
                string strPmtUrl = NSDLval.Substring(NSDLval.IndexOf("http"));
                if (strPmtId != String.Empty && strPmtUrl != String.Empty)
                {
                    URL = strPmtUrl.ToString() + "?PaymentID=" + strPmtId;
                }
                else
                {
                    return("Invalid Response!");
                }
                sr.Close();
            }
            Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write("Payment Redirection: " + URL);
            if (enrty > 0)
            {
                return(URL);
            }
            else
            {
                return(null);
            }

            #endregion Payment GateWay Flow
            //**********************************//
        }
        else
        {
            return(null);
        }
    }