arcgis server for js实现在具体的一点上空间查询

我想利用arcgis server for js在已经发布的要素服务上，实现在具体的一点上，如（经纬度为109.359,34.7161）的点上，实现多图层的空间查询，代码如下：，希望各位大神帮我看看怎么不行呀？
function doIdentify(evt) {
identifyTask = new esri.tasks.IdentifyTask(url);
identifyParams = new esri.tasks.IdentifyParameters();
identifyParams.tolerance = 0;
identifyParams.returnGeometry = true;
identifyParams.layerIds = [1, 30, 53];
identifyParams.layerOption = esri.tasks.IdentifyParameters.LAYER_OPTION_ALL;
var lc = new esri.geometry.Point(109.359,34.7161, { wkid: 4326 });
identifyParams.geometry =lc;
identifyParams.mapExtent = map.extent;
identifyTask.execute(identifyParams, function(idResults) { addToMap(idResults,lc); });
}