Simple stock chart with two datasets comparing

HTML

<script type="text/javascript" src="http://www.amcharts.com/lib/3/amcharts.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/serial.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/themes/none.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/amstock.js"></script>
<div id="chartdiv"></div>

CSS

#chartdiv {
	width	: 100%;
	height	: 500px;
}

JavaScript

var chartData = [];
generateChartData();


function generateChartData() {
	var firstDate = new Date();
	firstDate.setHours(0, 0, 0, 0);
	firstDate.setDate(firstDate.getDate() - 2000);

	for (var i = 0; i < 2000; i++) {
		var newDate = new Date(firstDate);

		newDate.setDate(newDate.getDate() + i);

		var open = Math.round(Math.random() * (30) + 100);
		var value1 = open + Math.round(Math.random() * (15) - Math.random() * 10);
		var value2 = Math.round(Math.random() * (30) + 100);

		chartData[i] = ({
			date: newDate,
			value1: value1,
			value2: value2
		});
	}
}

var chart = AmCharts.makeChart("chartdiv", {
	type: "stock",
    "theme": "none",
    pathToImages: "http://www.amcharts.com/lib/3/images/",

	dataSets: [{
		fieldMappings: [{
			fromField: "value1",
			toField: "value"
		}],

		color: "#7f8da9",
		dataProvider: chartData,
		title: "West Stock",
		categoryField: "date"
	}, {
		fieldMappings: [{
			fromField: "value2",
			toField: "value"
		}],
		color: "#fac314",
		dataProvider: chartData,
		compared: true,
		title: "East Stock",
		categoryField: "date"
	}],


	panels: [{
			title: "Value",
			showCategoryAxis: false,
			percentHeight: 70,
			valueAxes: [{
				dashLength: 5
			}],

			categoryAxis: {
				dashLength: 5
			},

			stockGraphs: [{
				id: "g1",
                type: "smoothedLine",
                compareGraphType: "smoothedLine",
				valueField: "value",
				lineColor: "#7f8da9",
                lineThickness: 2,
                compareGraphLineThickness: 2,
				comparable: true,
				compareField: "value"
			}],

			stockLegend: {
				//valueTextRegular: undefined,
				periodValueTextComparing: "[[percents.value.close]]%"
			}
		}
	],

	chartScrollbarSettings: {

		graph: "g1",
		graphType: "line",
		usePeriod: "WW"
	},

	periodSelector: {
		position: "bottom",
		periods: [{
			period: "DD",
			count: 10,
			label: "10 days"
		}, {
			period: "MM",
			selected: true,
			count: 1,
			label: "1 month"
		}, {
			period: "YYYY",
			count:...