Flex - ActionScript: how do I use SortField to sort my data numericly

public function SortField(name:String = null, caseInsensitive:Boolean = false, descending:Boolean = false, numeric:Object = null)

private function createXMLDataProvider():XMLListCollection{
    			var sort:Sort 	= new Sort();
    				sort.fields = [new SortField("@sortorder",true,false,true), new SortField("@label")];
    			var searchTypesCollection:XMLListCollection = new XMLListCollection(getAssociations(_appData.searchTypes, "category", searchType));
    				searchTypesCollection.sort = sort;
    				searchTypesCollection.refresh();
    		return 	searchTypesCollection;
    		}

sort.fields = [new SortField("@sortorder",true,false,true), new SortField("@label")];

var sortField:SortField = new SortField(value);
sortField.numeric = true;
sortField.descending = true;

var sort:Sort = new Sort();
sort.fields = [sortField];
xmlListColl.sort = sort;
return xmlListColl.refresh();

sort.fields = [new SortField("@sortorder",false,false,true), new SortField("@label")];