Php facebook app roatator

I have a facebook app that requires two unique inputs of data called the app ID and the app secret key. What I need is the php code to be modified so that it can rotate these arrays of app Ids and secret keys (in pairs). So the script would pick a pair of app Ids and secret from random from the list to be used in the application: ID1,secret1 ID2,secret 2 ID3,sercret3 etc