Highcharts.stockChart('container', {
    title: {
        text: 'chart.type is set to \'areaspline\''
    },
    chart: {
        type: 'areaspline'
    },

    rangeSelector: {
        selected: 1
    },

    series: [{
        name: 'USD to EUR',
        data: usdeur,
        threshold: null // default is 0
    }]
});