How to modify highcharts legend item click event?

Question

I need to modify click event on highcharts legend items. Highcharts demo http://www.highcharts.com/demo/line-basic . I want for example: first action will be some alert and

Answer 1

For me, the legendItemClick event had to be for the series, not the line. E.g.:

plotOptions: {
        series: {
            events: {
                legendItemClick: function(event) {
                    var visibility = this.visible ? 'visible' : 'hidden';
                    if (!confirm('The series is currently '+ 
                                 visibility +'. Do you want to change that?')) {
                        return false;
                    }
                }
            }
        }
    },

Example from Highcharts: http://jsfiddle.net/gh/get/jquery/1.7.2/highslide-software/highcharts.com/tree/master/samples/highcharts/plotoptions/series-events-legenditemclick/