Use working sample code and snippets to speed up your PayPal integrations. Download PHP, Java, and ASP.NET sample code for a range of PayPal products.
Integration Wizard

The Integration Wizard will generate code for your Express Checkout or Payflow integration:

* Express Checkout
* Express Checkout using Payflow Gateway
* Payflow - credit card processing

IPN/PDT

* Instant Payment Notification (IPN) sample code
* Payment Data Transfer (PDT) sample code

PayPal APIs

You can also download all the code samples (including supporting property and library files needed) for NVP or SOAP:

* Download all NVP sample code (zip, 112 KB)
* Download all SOAP sample code (zip, 84 KB)

Link:-
https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=develo...