myChart.setOption(option_science);
    var triggerAction = function(action, selected) {
        legend = [];
        for ( name in selected) {
            if (selected.hasOwnProperty(name)) {
                legend.push({name: name});
            }
        }
        myChart.dispatchAction({
            type: action,
            batch: legend
        });
    };

    // 是否選中其中一個
    var isOneUnSelect = function(selected) {

        var unSelectedCount = 0;
        for ( name in selected) {
            if (!selected.hasOwnProperty(name)) {
                continue;
            }

            if (selected[name] == false) {
                ++unSelectedCount;
            }
        }
        return unSelectedCount==1;
    };

    myChart.on('legendselectchanged', function(obj) {
        var selected = obj.selected;
        var legend = obj.name;

        // 使用 legendToggleSelect Action 會重新觸發 legendselectchanged Event，導致本函式重複執行
        // 使得 無 selected 物件
        if (selected != undefined) {
            if (isOneUnSelect(selected)) {
                triggerAction('legendSelect', selected);
            }
        }
        window.open('http://www.baidu.com');
    });