SortCompareFunction is not working in Flex

[Booma Devi]

Hi,

I am using flex version 4.5 and trying to test the sortCompareFunction.. But its not working.. Can any one please help me..?

Below is my mxml code:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
			   xmlns:s="library://ns.adobe.com/flex/spark" 
			   xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">
<fx:Script>
	<![CDATA[
		import mx.utils.ObjectUtil;
		import mx.events.FlexEvent;
		import spark.collections.Sort;
		import spark.collections.SortField;
		import spark.globalization.SortingCollator;
		
		private var collator:SortingCollator = new SortingCollator();
		
		private function sortCompareFunction(obj1:Object, obj2:Object, gc:GridColumn):int {
		
			collator.ignoreCase = true;
			return collator.compare(obj1[gc.dataField], obj2[gc.dataField]);
		}

	
		
	]]>
</fx:Script>
	<fx:Declarations>
		
		<s:ArrayList id="PersonList">
			<fx:Object name="Dan Florio" 	    typeofperson="polyGeek" />
			<fx:Object name="David Ortinau" 	typeofperson="davidortinau" />
			<fx:Object name="Simeon Bateman" 	typeofperson="simBateman" />
			</s:ArrayList>
	</fx:Declarations>


	<s:DataGrid id="dg" x="294" y="152" width="30%" height="30%"
				alternatingRowColors="[ #eeeeFF, #eeFFee, #FFeeee ]" dataProvider="{PersonList}"
				editable="true" requestedRowCount="-40">
		
		<s:columns>
			<s:ArrayList>
				<!-- dataField has beent taken from the object's properties -->
				<s:GridColumn dataField="name" headerText="NAME" />
				<s:GridColumn dataField="typeofperson" headerText="TYPE OF PERSON" sortCompareFunction="sortCompareFunction"/>
				</s:ArrayList>
		</s:columns>
	</s:DataGrid>

</s:Application>