stock drawing trend lines

HTML

<script src="http://www.amcharts.com/lib/amstock.js" type="text/javascript"></script>
<div id="chartdiv" style="width: 100%; height: 370px;"></div>

CSS

body
{
    font-size:12px;
    color:#000000;
    background-color:#ffffff;
    font-family:verdana,helvetica,arial,sans-serif;
}

.amChartsButtonSelected
{
   background-color:#CC0000;
   border-style:solid;
   border-color:#CC0000;
   border-width:1px;
   color:#FFFFFF;
  -moz-border-radius: 5px;
  border-radius: 5px;
  margin: 1px;   
    padding:3px;
}

.amChartsButton
{
   background-color:#EEEEEE;
   border-style:solid;
   border-color:#CCCCCC;
   border-width:1px;
   color:#000000;
  -moz-border-radius: 5px;
  border-radius: 5px;
  margin: 1px;  
    padding:3px;
}

.amChartsCompareList
{
   border-style:solid;
   border-color:#CCCCCC;
   border-width:1px;
}

JavaScript

var chartData = [];

function generateChartData() {
    var date = new Date(2012, 0, 1);
    date.setDate(date.getDate() - 500);
    date.setHours(0, 0, 0, 0);

    for (var i = 0; i < 500; i++) {
        var newDate = new Date(date);
        newDate.setDate(newDate.getDate() + i);

        var value = Math.round(Math.random() * (40 + i)) + 200 + i;

        chartData.push({
            date: newDate,
            value: value
        });
    }
}

AmCharts.ready(function() {
    generateChartData();
    createStockChart();
});


function createStockChart() {
    var chart = new AmCharts.AmStockChart();
    chart.pathToImages = "http://www.amcharts.com/lib/images/";

    // DATASETS //////////////////////////////////////////
    var dataSet = new AmCharts.DataSet();
    dataSet.color = "#b0de09";
    dataSet.fieldMappings = [{
        fromField: "value",
        toField: "value"}];
    dataSet.dataProvider = chartData;
    dataSet.categoryField = "date";

    chart.dataSets = [dataSet];

    // PANELS ///////////////////////////////////////////                                                  
    var stockPanel = new AmCharts.StockPanel();
    stockPanel.showCategoryAxis = true;
    stockPanel.title = "Value";
    stockPanel.eraseAll = false;
    stockPanel.addLabel(0, 100, "Click on the pencil icon on top-right to start drawing", "center", 16);

    var graph = new AmCharts.StockGraph();
    graph.valueField = "value";
    graph.bullet = "round";
    stockPanel.addStockGraph(graph);

    var stockLegend = new AmCharts.StockLegend();
    stockLegend.valueTextRegular = " ";
    stockLegend.markerType = "none";
    stockPanel.stockLegend = stockLegend;
    stockPanel.drawingIconsEnabled = true;

    chart.panels = [stockPanel];


    // OTHER SETTINGS ////////////////////////////////////
    var scrollbarSettings = new AmCharts.ChartScrollbarSettings();
    scrollbarSettings.graph = graph;
    scrollbarSettings.updateOnReleaseOnly = true;
   ...