Adwords and Paypal Conversion help

Hello, need the assistance of a programmer that has successfully installed Google Adwords conversion tracking. Here is the problem I am facing. When I installed the Google Adwords conversion tracking code on my checkout page (before the customer actually purchased), it worked and tracked in adwords when a customer landed on the checkout page. However, when I installed the conversion tracking code on my thankyou page (after the user has purchased and returned from paypal to my return URL), it doesn't track those conversions. I don't necessarily need to see the amount of sale in the conversion reporting, just the number of conversions. Looking for someone that can help right now. Payment via GAF escrow only. Communication via MSN messenger.