paypal integration using php

i have followed the steps form the following link https://www.paypal-labs.开发者_Go百科com/integrationwizard/ecpaypal/main.php to integrate paypal for my website, its working good, after successful transaction it redirect to a specified php page with a token and a payerID.... what should do with that token? i dont know what is the use of it? will it help me to process further?

Thanks,

GetExpressCheckoutDetails and DoExpressCheckoutPayment

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