Bar charts with background horizontal bars

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 charts to show up:

<canvas id="cvs" width="600" height="250">[No canvas support]</canvas><br />
<canvas id="cvs2" width="600" height="250">[No canvas support]</canvas>

This is the code that generates the chart:

<script>
    window.onload = function ()
    {
        var bar = new RGraph.Bar({
            id: 'cvs',
            data: [[21,31],[13, -5],[-12, -58],[5, 29],[59, 28],[40, 10]],
            options: {
                colors: ['blue', 'red'],
                xaxispos: 'center',
                labels: ['2007', '2008', '2009', '2010', '2011', '2012'],
                backgroundHbars: [
                    [-55,-5,'rgba(255,0,0,0.2)'],
                    [-45,-10,'rgba(255,255,0,0.2)'],
                    [-45,90,'rgba(0,255,0,0.2)'],
                    [45,10,'rgba(255,255,0,0.2)'],
                    [55,null,'rgba(255,0,0,0.2)']
                ],
                strokestyle: 'rgba(0,0,0,0)',
                textAccessible: true
            }
        }).draw();

        var bar2 = new RGraph.Bar({
            id: 'cvs2',
            data: [[21,31],[13, 5],[12, 19],[5, 29],[59, 28],[40, 10]],
            options: {
                colors: ['blue', 'red'],
                labels: ['2007', '2008', '2009', '2010', '2011', '2012'],
                backgroundHbars: [
                    [-55,-5,'rgba(255,0,0,0.2)'],
                    [-45,-10,'rgba(255,255,0,0.2)'],
                    [-45,90,'rgba(0,255,0,0.2)'],
                    [45,10,'rgba(255,255,0,0.2)'],
                    [55,null,'rgba(255,0,0,0.2)']
                ],
                strokestyle: 'rgba(0,0,0,0)',
                textAccessible: true
            }
        }).draw();
    };
</script>