title: Tracking custom IFRAME events in Google Tag Manager
body: <p>I have some IFRAMEs on my pages for external services -- AddThis, YouTube, and a JWPlayer-based custom video solution.  I want to use GTM to track clicks and responses in those IFRAMEs (particularly 'play' events on the video) but the cross-domain policy prevents that.  How do I make that work -- and how do I get it to work in GTM?</p>