Chartdirector variables addExtraField2

$chartImageMap = $c->getHTMLImageMap("xystub.php", "",    "title='{dataSetName} @ {xLabel} = USD {value|0} millions'");$revenue = array(4500, 5600, 6300, 8000, 12000, 14000, 16000, 20000, 24000, 28000);$grossMargin = array(62, 65, 63, 60, 55, 56, 57, 53, 52, 50);$backLog = array(563, 683, 788, 941, 1334, 1522, 1644, 1905, 2222, 2544);$labels = array("1996", "1997", "1998", "1999", "2000", "2001", "2002", "2003",    "2004", "2005");# Add extra field to the bars. These fields are used for showing additional# information.$layer->addExtraField2($grossMargin);$layer->addExtraField2($backLog);# Client side Javascript to show detail information "onmouseover"$showText = "onmouseover='showInfo(\"{xLabel}\", {value}, {field0}, {field1});' ";