Flex DataGrid Tooltip dataTipFunction Example

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="doInit();">
<mx:Script>
<!![CDATA[import mx.collections.ArrayCollection; // this holds the grid data
[Bindable]
private var myData:ArrayCollection = new ArrayCollection();private function doInit():void{
myData.addItem({fname:"Joe",lname:"Bloggs"});
myData.addItem({fname:"Joe1",lname:"Bloggs"});
}

private function buildToolTip(item:Object):String{
var myString:String = "";
if(item != null)
{
myString = myString + "Firstname : " + item.fname + "\n";
myString = myString + "Lastname : " + item.lname + "\n"
}
return myString;
}
]]>
</mx:Script>
<mx:DataGrid id="dGrid"  dataProvider="{myData}"  visible="true" dataTipFunction="buildToolTip">
<mx:columns>
<mx:DataGridColumn dataField="fname" headerText="FirstName" showDataTips="true" />
<mx:DataGridColumn dataField="lname" headerText="LastName" showDataTips="true" />
</mx:columns>
</mx:DataGrid>
</mx:Application>