FusionCharts - Set Chart Data with user input

Created using FusionCharts Suite XT - www.fusioncharts.com

HTML

<script src="http://static.fusioncharts.com/code/latest/fusioncharts.js"></script>
<script src="http://static.fusioncharts.com/code/latest/fusioncharts.charts.js"></script>
<!-- Column 2D chart showing Monthly revenues for last year -->
<div id="chart-container">FusionCharts will render here</div>
<div>
     <h5>Set the Footfall</h5>

    <select id="monthSelector">
        <option value="Jan">Jan</option>
        <option value="Feb">Feb</option>
        <option value="Mar">Mar</option>
    </select>
    <input type="range" min="0" max="100" value="0" id="slider" />
</div>

CSS

h5 {
    margin: 10px 0;
}

JavaScript

FusionCharts.ready(function() {
    var chartConfig = {
            "caption": "Total footfall in Bakersfield Central - Admin View",
            "subCaption": "Year 2014",
            "xAxisName": "Month",
            "yAxisName": "No. of Visitors",

            //Cosmetics
            "lineThickness": "2",
            "paletteColors": "#0075c2",
            "baseFontColor": "#333333",
            "baseFont": "Helvetica Neue,Arial",
            "captionFontSize": "14",
            "subcaptionFontSize": "14",
            "subcaptionFontBold": "0",
            "showBorder": "0",
            "bgColor": "#ffffff",
            "showShadow": "0",
            "canvasBgColor": "#ffffff",
            "canvasBorderAlpha": "0",
            "divlineAlpha": "100",
            "divlineColor": "#999999",
            "divlineThickness": "1",
            "divLineIsDashed": "1",
            "divLineDashLen": "1",
            "divLineGapLen": "1",
            "showXAxisLine": "1",
            "xAxisLineThickness": "1",
            "xAxisLineColor": "#999999",
            "showAlternateHGridColor": "0",
            "yAxisMinValue": "0",
            "yAxisMaxValue": "100",
            "animation": "0"
        },
        chartData = [{
            "label": "Jan",
            "value": "42"
        }, {
            "label": "Feb",
            "value": "81"
        }, {
            "label": "Mar",
            "value": "36"
        }],
        revenueChart = new FusionCharts({
            type: 'line',
            renderAt: 'chart-container',
            width: '550',
            height: '350',
            dataFormat: 'json',
            dataSource: {
                "chart": chartConfig,
                "data": chartData
            }
        });
    revenueChart.render();
    document.getElementById('slider').oninput = function() {
    alert ('hello');
        var currentData = revenueChart.getJSONData(),
            selectedMonth =...