A demo of the dotted or dashed background grid

This uses the relatively new addition to canvas from the canvas v5 specification - native dotted and dashed lines. As browsers add support you will be able to use the option in them but currently (May 2013) it's only supported in Chrome. 

obj.Set('backgroundGridDashed', true);
obj.Set('backgroundGridDotted', true);
[No canvas support] [No canvas support]

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="cvs1" width="600" height="250">[No canvas support]</canvas>
<canvas id="cvs2" width="600" height="250">[No canvas support]</canvas>
This is the code that generates the chart: