Highlighting the Line chart

By using two lines - the second with a smaller linewidth than the first, but using the same values as the first - the second is drawn on top of the first.

[No canvas support]

This goes in the documents header:
<script src="RGraph.common.core.js"></script>
<script src="RGraph.common.dynamic.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:
<script>
    line = new RGraph.Line({
        id: 'cvs',
        data: [
            [4,5,3,8,null,9,6,5,3],
            [4,5,3,8,null,9,6,5,3]
        ],
        options: {
            xaxisLabels: ['Mal', 'Barry', 'Gary', 'Neil', 'Kim', 'Pete', 'Lou', 'Fred', 'Jobe'],
            colors: ['black', 'white'],
            linewidth: [5,2],
            hmargin: 5,
            shadowOffsetx: 0,
            shadowOffsety: 0,
            shadowBlur: 15,
            tickmarksStyle: null
        }
    }).draw();
</script>