function startEmbeddedIframe( event ) {

		var iframe = event.target;

		// YouTube postMessage API
		if( /youtube\.com\/embed\//.test( iframe.getAttribute( 'src' ) ) && iframe.hasAttribute( 'data-autoplay' ) ) {
			iframe.contentWindow.postMessage( '{"event":"command","func":"playVideo","args":""}', '*' );
		}
		// Vimeo postMessage API
		else if( /player\.vimeo\.com\//.test( iframe.getAttribute( 'src' ) ) && iframe.hasAttribute( 'data-autoplay' ) ) {
			iframe.contentWindow.postMessage( '{"method":"play"}', '*' );
		}
		// Generic postMessage API
		else {
			iframe.contentWindow.postMessage( 'slide:start', '*' );
		}

	}
"Starts" the content of an embedded iframe using the
postmessage API.