Flex 操作命名空间

public function equalSearch(url:String,layerNameEng:String,searchField:String,value:String):void{if(url == "" || layerNameEng == "" || searchField == "")return;var _request:XMLRequest = new XMLRequest(url,onSuccess,onFailure);var postXML:XML = <wfs:GetFeature service="WFS" version="1.0.0" outputFormat="GML2"  xmlns:topp="http://www.openplans.org/topp"   xmlns:wfs="http://www.opengis.net/wfs"  xmlns:ogc="http://www.opengis.net/ogc"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://www.opengis.net/wfs http://schemas.opengis.net/wfs/1.0.0/WFS-basic.xsd">  <wfs:Query><ogc:Filter><ogc:PropertyIsEqualTo></ogc:PropertyIsEqualTo ></ogc:Filter>  </wfs:Query></wfs:GetFeature>var ogc:Namespace = postXML.namespace("ogc");var wfs:Namespace = postXML.namespace("wfs");postXML.wfs::Query.@typeName = layerNameEng;postXML.wfs::Query.ogc::Filter.ogc::PropertyIsEqualTo.ogc::PropertyName = searchField;postXML.wfs::Query.ogc::Filter.ogc::PropertyIsEqualTo.ogc::Literal = value;_request.postContent = postXML;_request.duration = 0;_request.send();_myXMLRequest.xmlRequestArr.push(_request);}