Updating stock chart title showing current selection

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;
    font-size: 11px;
}

JavaScript

var chartData = generateChartData();

function generateChartData() {
	var chartData = [];
	var firstDate = new Date(2012, 0, 1);
	firstDate.setDate(firstDate.getDate() - 1000);
	firstDate.setHours(0, 0, 0, 0);

	for (var i = 0; i < 1000; i++) {
		var newDate = new Date(firstDate);
		newDate.setHours(0, i, 0, 0);

		var a = Math.round(Math.random() * (40 + i)) + 100 + i;
		var b = Math.round(Math.random() * 100000000);

		chartData.push({
			date: newDate,
			value: a,
			volume: b
		});
	}
	return chartData;
}

var chart = AmCharts.makeChart("chartdiv", {

		type: "serial",
        "theme": "none",
        pathToImages: "http://www.amcharts.com/lib/3/images/",

		categoryAxesSettings: {
			minPeriod: "mm"
		},

		dataSets: [{
			color: "#b0de09",
			fieldMappings: [{
				fromField: "value",
				toField: "value"
			}],

			dataProvider: chartData,
			categoryField: "date"
		}],


		panels: [{
            titles: [{
                text: "Panel title: "
            }],
				showCategoryAxis: false,
				title: "Value",
				percentHeight: 70,

				stockGraphs: [{
					id: "g1",
					valueField: "value",
					type: "smoothedLine",
					lineThickness: 2,
					bullet: "round"
				}],


				stockLegend: {
					markerType: "none"
				}
			},

			{
				title: "Volume",
				percentHeight: 30,
				stockGraphs: [{
					valueField: "volume",
					type: "column",
					cornerRadiusTop: 2,
					fillAlphas: 1
				}],

				stockLegend: {
					markerType: "none"
				}
			}
		],

		chartScrollbarSettings: {
			graph: "g1",
			usePeriod: "10mm",
		},

		chartCursorSettings: {
			valueBalloonsEnabled: true
		},

		periodSelector: {
			position: "bottom",
			dateFormat: "YYYY-MM-DD JJ:NN",
			inputFieldWidth: 150,
			periods: [{
				period: "hh",
				count: 1,
				label: "1 hour",
				selected: true

			}, {
				period: "hh",
				count: 2,
				label: "2 hours"
			}, {
				period: "hh",
				count: 5,
				label: "5 hour"
			}, {
				period: "hh",
				count: 12,
				label: "12 hours"
			},...