slides in XML



  <document>
  ...
  <slide id="1">
  <text>
  <line>What about the slide format?</line>
  <break/>
  <line>yeh, what about it"?</line>
  </text>
  <vrml>Sphere { radius 0.5 }</vrml>
  </slide>
  ...
  <slide id="2">
  <vrml>Sphere { radius 0.5 }</vrml>
  </slide>
  ...
  </document>