A Fuel chart fetching its reading via AJAX

Note: For security reasons the AJAX demos don't work offline. You can view the demos on the RGraph website here: https://www.rgraph.net/demos/index.html

This goes in the documents header:

<script src="RGraph.common.core.js"></script>
<script src="RGraph.fuel.js"></script>

Put this where you want the chart to show up:

<canvas id="cvs" width="200" height="200">
    [No canvas support]
</canvas>

This is the code that generates the chart: