Although it is not completely clear what other code you have on the page, it might be that you are missing the javascript references. These must be on t heir place. Like this:
<title>Sparklines - usage | shieldui.com</title>
<link rel="stylesheet" type="text/css" href="../../../css/shieldchart.css" />
<script src="../../../../external/jquery-1.8.2.min.js" type="text/javascript"></script>
<script src="../../../../external/jquery.mousewheel/jquery.mousewheel.js" type="text/javascript"></script>
<script src="../../../../external/canvg-1.2/rgbcolor.js" type="text/javascript"></script>
<script src="../../../../external/canvg-1.2/canvg.js" type="text/javascript"></script>
<script src="../../../../external/globalize/globalize.js" type="text/javascript"></script>
<script src="../../../../common/core.js" type="text/javascript">//</script>
<script src="../../../js/shieldchart.js" type="text/javascript">//</script>