Advanceddatagrid Group so that the first row shows the data

<?xml version= "1.0" encoding= "Utf-8"?> <mx:application xmlns:mx= "Http://www.adobe.com/2006/mxml" Vertical "> <mx:Script> <!
			[cdata[import Mx.controls.advancedDataGridClasses.AdvancedDataGridColumn;
			
			Import mx.collections.ArrayCollection; [bindable] private var dphierarchy:arraycollection = new ArrayCollection ([{province: "Hubei Province", Daihao: "$", Tel: "1234567") 8900 ", Citys: [{city:" Wuhan ", Daihao:" 027 ", Tel:" 027-88880000 "}, {city:" Xianning ", Daihao:" 0715 ", Tel:" 0715-66 660000 "}]}, {province:" Henan Province ", Daihao:" 001 ", Tel:" 12345678901 ", Citys: [{city:" Zhengzhou ", Daihao:" 03
			
			
			", Tel:" 0371-66668888 "}]});
			Private Function Adglabelfunc (Item:object, Column:advanceddatagridcolumn): string{return item.province; 
		}]]> </mx:Script> <mx:advanceddatagrid width= "100%" height= "100%" grouplabelfunction= "Adglabelfunc" > <mx:dataProvider> <mx:hierarchicaldata source= "{Dphierarchy} "childrenfield=" Citys/> </mx:dataProvider> <mx:columns> <mx:advanceddatagridcolumn datafield= "City" headertext= "name"/> <mx:advanceddatagridcolumn datafield= "Daihao" headertext= "area code"/> &LT;MX: Advanceddatagridcolumn datafield= "Tel" headertext= "tel"/> </mx:columns> </mx:AdvancedDataGrid> </ Mx:application>