Authorize.net ARB automated recurring billing integration

Php curl was used to post XML to the authorize.net payment gateway.

Authorize.net automated recurring billing arb api (http://www.authorize.net/solutions/merchantsolutions/merchantservices/automatedrecurringbilling/) was integrated into an events management php script

Users have the ability to create an authorize.net arb subscription and edit the subscription if their credit card details changes and finally cancel their subscription too.

User's credit card details are NOT stored in the server but passed along to authorize.net.