A stacked Bar chart with chart.labels.above

This goes in the documents header:
<script src="RGraph.common.core.js"></script>
<script src="RGraph.bar.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>
    new RGraph.Bar({
        id: 'cvs',
        data: [[10,12,13],[45,43,26],[42,21,52],[4,3,5]],
        options: {
            xaxisLabels: ['January','February','March','April'],
            labelsAbove: true,
            labelsAboveUnitsPre: '',
            labelsAboveUnitsPost: '',
            hmargin: 20,
            hmarginGrouped: 2,
            highlightFill: 'red',
            grouping: 'stacked',
            shadowOffsetx: 2,
            shadowOffsety: 2,
            shadowBlur: 2,
            colorsStroke: 'rgba(0,0,0,0)',
            marginLeft: 35
        }
    }).draw();
</script>