example



   <par>
      <a href="#Story"> <img src="button1.jpg"/> </a>
      <a href="#Weather"> <img src="button2.jpg"/></a>
       <excl>
           <par id="Story" begin="0s">
             <video src="video1.mpg"/>
             <text src="captions.html"/>
           </par>
  
           <par id="Weather">
             <img src="weather.jpg"/>
             <audio src="weather-rpt.mp3"/>
           </par>
       </excl>
   </par>