https://sites.google.com/a/google.com/adsense-ui/Home/expand...
Expandable Ads API Last updated: Jan 12, 2009 11:43 AM For an expandable creative to work in GCN, the creative designer must implement the GCN Expandable Ads API. All of the expansion animation logic will be handled by the creative designer, however, they need to incorporate our API into their creative to ensure that the ad's enclosing iframe can expand and collapse when served in GCN.
Contents 1 How to Create a GCN Expandable Ad 2 How to Test a GCN Expandable Ad
How to Create a GCN Expandable Ad 1. Expandable creative must be contained within a JavaScript file, as it will be served via a