Hi, I'm working with the HighCharts library and I've been trying to create a legendItemClick function for one of my series, so that when it's label is clicked it will change the opacity for the other series. I'm not quite sure how to get this working.

Here's the code I'm using and a jsfiddle of that code.

Code:
chart = new Highcharts.Chart({
        chart: {
            renderTo: 'container',
            marginRight: 130,
            marginBottom: 25
        },
        xAxis: {
            categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
                'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
        },
        yAxis: {
            title: {
                text: 'Temperature (C)'
            },
            plotLines: [{
                value: 0,
                width: 1,
                color: '#808080'
            }]
        },
        tooltip: {
            formatter: function() {
                    return '<b>'+ this.series.name +'</b><br/>'+
                    this.x +': '+ this.y +'C';
            }
        },
        legend: {
            layout: 'vertical',
            align: 'right',
            verticalAlign: 'top',
            x: -10,
            y: 100,
            borderWidth: 0
        },
        series: [{
            name: 'Tokyo',
            type: 'area',
            events: {
                legendItemClick: function() {
                                chart.series[1].fillOpacity = 0.75;
                                chart.redraw();
                }
            },
            data: [7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2, 26.5, 23.3, 18.3, 13.9, 9.6]
        }, {
            name: 'New York',
            type: 'area',
            fillOpacity: '0.01',
            data: [-0.2, 0.8, 5.7, 11.3, 17.0, 22.0, 24.8, 24.1, 20.1, 14.1, 8.6, 2.5]
        },
          {
            name: 'New York',
            type: 'area',
            fillOpacity: '0.01',
            data: [-0.2, 0.8, 5.7, 11.3, 17.0, 22.0, 24.8, 24.1, 20.1, 14.1, 8.6, 2.5]
        }]
    });