asp.net - Paypal adaptive payment return url is calling twice -

i have implemented paypal adaptive payment method , using web flow. after making payment, when explicitly clicks on return button, return url calls twice if wait auto redirect calls once only.

i not able understand why return url calling twice.

please advice.

i using below code.

public static actionoutput maketransactionusingpaypal(paymentdetails payment, shopcart shop_cart) {     receiverlist receiverlist = new receiverlist();     receiverlist.receiver = new list<receiver>();     string action_type = "pay_primary";     decimal amnt_to_admin = ((shop_cart.totalamounttobepaid * 10) / 100);      /*total amount admin account */     receiver rec1 = new receiver(shop_cart.totalamounttobepaid);     rec1.email = config.adminpaypalbusinessaccount;     rec1.primary = true;      /*amount after deducting admin commision seller */     receiver rec2 = new receiver(math.round((shop_cart.totalamounttobepaid - amnt_to_admin), 2, midpointrounding.toeven));     rec2.email = payment.paypalemail; // "anuj_merchant@xicom.biz";      receiverlist.receiver.add(rec1);     receiverlist.receiver.add(rec2);     payrequest req = new payrequest(new requestenvelope("en_us"), action_type, config.paypalcancelurl, "usd", receiverlist, config.paypalreturnurl);      // set. fire request                 adaptivepaymentsservice service = new adaptivepaymentsservice();      payresponse resp = null;     //transactiondetail details = new transactiondetail();      resp = service.pay(req);     string paykey = resp.paykey;     string paymentstatus = resp.paymentexecstatus;     responseenvelope responseenvelope = resp.responseenvelope;     payerrorlist errorlist = resp.payerrorlist;     list<errordata> errordata = resp.error;     if (errordata.count > 0)     {         return new actionoutput         {             status = actionstatus.error,             message = errordata[0].message         };     }     fundingplan defaultfundingplan = resp.defaultfundingplan;     warningdatalist warningdatalist = resp.warningdatalist;     string redirecturl = null;     if (!(resp.responseenvelope.ack == ackcode.failure) &&         !(resp.responseenvelope.ack == ackcode.failurewithwarning))     {         redirecturl = configurationmanager.appsettings["paypal_redirect_url"] + "_ap-payment&paykey=" + resp.paykey;      }     return new actionoutput     {         status = actionstatus.successfull,         message = "redirecting paypal...",         results = new list<string> { redirecturl, resp.paykey }     }; } 

@jitendra, had same issue , found out paypal uses server side script redirects user return url after while , when explicitly click on return button, paypal server script again hits return url on own 2 responses/hits on our return url.

we can on checking/maintaining no of responses after payments made on paypal.

we can maintain using cookies on client end or on server using sessions or else similar.

hope helps well.