<?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>