[Solved]-How to get multiple data series into Highcharts-Highcharts

$.getjson is an asynchronous request. once you receive the data, then you can pass it to highcharts, thus you have to call that code from within the callback function of $.getjson().

try this, use a helper function to process your data and draw the chart, see drawchart() below:

var options1 = {
    chart: {
        renderto: 'container1'
    },
    series: []
};

var drawchart = function(data, name) {
    // 'series' is an array of objects with keys: 
    //     - 'name' (string)
    //     - 'data' (array)
    var newseriesdata = {
        name: name,
        data: data
    };

    // add the new data to the series array
    options1.series.push(newseriesdata);

    // if you want to remove old series data, you can do that here too

    // render the chart
    var chart = new highcharts.chart(options1);
};

$.getjson('tokyo.jsn', function(data){
    drawchart(data, 'tokyo');
});
$.getjson('sydney.jsn', function(data){
    drawchart(data, 'sydney');
});

see fiddle: http://jsfiddle.net/amyamy86/pum7s/

you can use solution used by highcharts in that example: http://www.highcharts.com/stock/demo/compare

or first create empty chart, without any series, and then use addseries() function in each callback, see: http://api.highcharts.com/highcharts#chart.addseries()