W3C Talk - slide "Example (2)"

    ...
    <body>
        <seq>        
            <par begin="1s" dur="2s">
                <switch>        
                    <img customTest="fred" src="../images/smile.jpg"/>
                    <img src="../images/frown.jpg"/>
                </switch>
            </par>
            <par begin="1s" dur="2s">
                <switch>        
                    <img customTest="barney" src="../images/smile.jpg"/>
                    <img src="../images/frown.jpg"/>
                </switch>
            </par>
          </seq>        
    </body>
</smil>