<?xml version=“1.0” standalone=“yes”?> <smil>

<body>

<!– The SMIL <switch> element will process the

     first child element which tests true and skip
     past all others. -->
<switch>

<!– The system-required attribute tests to see if

     the user agent supports SVG. If true, then
     render the file drawing.svg. -->
<ref system-required="http://www.w3.org/Graphics/SVG/svg-19990412.dtd" type="image/svg" src="drawing.svg"/>

<!– Else, render the alternate image. –>

    <img src="alternate_image.jpg"/>
  </switch>
</body>

</smil>