<?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>
