A dynamically updating Line chart showing values for the last 10 minutes (1 per second)

Note Because Chrome slows down timers when it's in the background - this chart can occasionally miss out X values when the browser is in the background or is minimised. So for that reason - if you're running this, or another timer based updating chart, then you're advised to use a browser other than Chrome (or if in Chrome keep it in the foregound).

[No canvas support]
Current seconds:
0

This goes in the documents header: 
<script src="RGraph.common.core.js"></script>
<script src="RGraph.line.js"></script>
Put this where you want the chart to show up: 
<canvas id="cvs" width="800" height="250">
    [No canvas support]
</canvas>
This is the code that generates the chart: