By using the Poly drawing API object with a filled range chart you can make the filled range clickable.
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="600" height="250">
[No canvas support]
</canvas>
This is the code that generates the chart: