title: How to implement DoDirectPayment in paypal using c#
body: <p>I am newbie to paypal. I want to implement direct payment api for my website. Means i will be having a buy button when i click on that it will expand and in that iframe i will be having the url for paypal direct payment. I have written the code like</p>
  
  <pre><code>     string address = "https://api-3t.sandbox.paypal.com/nvp?USER=user&amp;COUNTRYCODE=US&amp;ZIP=95131&amp;STATE=CA&amp;CITY=San Jose&amp;FIRSTNAME=John&amp;LASTNAME=Smith&amp;STREET=1asfasdfSt&amp;CVV2=123&amp;ACCT=4683075410516684&amp;IPADDRESS=192.168.0.62&amp;PWD=1357635822&amp;EXPDATE=042011&amp;VERSION=58.0&amp;SIGNATURE=signature&amp;METHOD=DoDirectPayment&amp;CREDITCARDTYPE=Visa&amp;AMT=10.00&amp;PAYMENTACTION=Sale&amp;RETURNURL=http://returnurl&amp;CANCELURL=http://cancnelurl";
  
          HttpWebRequest request = (HttpWebRequest)WebRequest.Create(address);
          HttpWebResponse response2 = (HttpWebResponse)request.GetResponse();
          Stream stream = response2.GetResponseStream();
          StreamReader rdr = new StreamReader(stream);
          string req = rdr.ReadToEnd();
  </code></pre>
  
  <p>But the <code>req</code> contains the failure message. I don't know what credentials i am missing.
  Any help is appreciated.</p>