Integration Guide

Table Of Contents
November 20055
Contents
Downloading PayPal's Public Certificate. . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Removing Your Public Certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Blocking Unencrypted Website Payments . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Chapter 6 Testing in the PayPal Sandbox . . . . . . . . . . . . . . .89
Chapter 7 Website Payments Standard HTML FORM Basics . . . . . .91
FORM Attributes: ACTION and METHOD . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Hidden Input Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Specifying the Website Payments Standard Product: cmd . . . . . . . . . . . . . . . . . 92
Variations on Basic Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Prompting for Quantity in Buy Now or Donations: undefined_quantity . . . . . . . . . 92
Recordkeeping with Passthrough Variables . . . . . . . . . . . . . . . . . . . . . . . 92
Setting the Character Set: charset. . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Setting Return URL on Individual Transactions . . . . . . . . . . . . . . . . . . . . . 93
Desired Currency on Individual Transactions . . . . . . . . . . . . . . . . . . . . . . 93
URL-Encoding Variable Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Prepopulating FORMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Sample HTML for FORM Prepopulation . . . . . . . . . . . . . . . . . . . . . . . . . 94
Overriding PayPal-Stored Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Sample HTML for Overriding PayPal-Stored Shipping Addresses . . . . . . . . . . . 95
Instant Payment Notification: notify_url . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Appendix A Website Payments Standard HTML Variables . . . . . . . .99
Appendix B Country Codes . . . . . . . . . . . . . . . . . . . . . . 109
ISO 3166 Standard Country Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113