Source of improve.Smil
<smil xmlns="http://www.w3.org/2001/SMIL20/Language">
<head>
<meta name = "title"
content = "base and fill concepts" />
<!-- the base tag determines how relative references work -->
<meta name = "base"
content = "http://www.cs.iupui.edu/~aharris/n351/smil20/" />
<layout>
<root-layout height = "300"
width = "400"
backgroundColor = "blue" />
<region id = "mainRgn"
left = "10%"
top = "5%"
height = "70%"
width = "80%"
backgroundColor = "red"
fit = "meet" />
<region id = "textRgn"
left = "10%"
top = "80%"
height = "15%"
width = "80%"
backgroundColor = "green" />
<!-- define a center registration point -->
</layout>
</head>
<body>
<seq>
<par>
<img src = "now.gif"
region = "mainRgn"
dur = "5s"
regPoint = "center"
regAlign = "center" />
<!-- note I replace spaces with %20 -->
<text src = "data:text/plain,This%20is%20how%20I%20look%20now"
region = "textRgn"
dur = "5s"/ >
</par>
<par>
<img src = "face.gif"
region = "mainRgn"
dur = "5s"
regPoint = "center"
regAlign = "center" />
<text src = "data:text/plain,This%20is%20how%20I%20look%20before%20I%20shave"
region = "textRgn"
dur = "5s"/ >
</par>
</seq>
</body>
</smil>