buffer analyst has non effect, here is my code, please help me

WangYafei — Thu, 01 Aug 2013 03:29:50 GMT

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>Simple Map</title>
    <link rel="stylesheet" type="text/css" href="esri/js/dojo/dijit/themes/claro/claro.css"/>
    <link rel="stylesheet" type="text/css" href="esri/js/esri/css/esri.css" />
    <script type="text/javascript" src="esri/init.js"></script>
    <script type="text/javascript">
     //????????????????????????????
require(["esri/map","dojo/parser","dojo/on","dojo/dom","dojo/_base/Color",
"dojo/_base/array","esri/geometry/Extent","esri/tasks/GeometryService","esri/dijit/Scalebar",
     "dijit/layout/BorderContainer","dijit/layout/ContentPane","esri/layers/FeatureLayer",
     "esri/symbols/SimpleFillSymbol","esri/symbols/SimpleLineSymbol","esri/graphic",
     "dijit/TitlePane","esri/dijit/BasemapGallery","esri/dijit/OverviewMap",
     "esri/tasks/BufferParameters",
     "dojo/domReady!"], function(Map,parser,on,dom,Color,Array,Extent,GeometryService){
   //????????????????dijit????
   parser.parse();
   //????????????????????????????????
   var initExtent = new esri.geometry.Extent({
    "xmin":73.595722,
    "ymin":18.2407366,
    "xmax":134.7725712,
    "ymax":53.482465,
    "spatialReference":{"wkid":102100}
   });
   //????????????????????????????id="mapDiv"?????????
   var myMap = new esri.Map("mapDiv",{
    basemap : "topo", //??????????url???????esri??????????topo,satellite????????
    extent : initExtent, //???????????
    logo : false, //????????esri???logo
    //nav : true, //????????????????????????????????
    navigationMode : "css-transforms",
    center : [-255.255, 35.022],
    zoom : 5, //????????
    slideStyle : "small"
   });

   var featureLayer = new esri.layers.FeatureLayer("http://192.168.1.142/ArcGIS/rest/services/chinaarea/chinaarea/MapServer/0",{
    mode: esri.layers.FeatureLayer.MODE_ONDEMAND,
    outFields: ["*"]
   });

   myMap.addLayer(featureLayer);

   //??????????????
   var baseMapGallery = new esri.dijit.BasemapGallery({
    showArcGISBasemaps : true, //????ArcGIS????????
    map : myMap //????????map??
   }, "baseMapGallery"); //baseMapGallery?????????????
   //??????????????????????????????????????
   baseMapGallery.startup();
   //????dojo/on???????????????????????????????
   on(baseMapGallery, "onError", function(msg){
    console.log(msg);
   });

   //????????????????????????????????????????????????????????????????
   on(myMap, "load", function(){
    //???????????
    var overviewMap = new esri.dijit.OverviewMap({
     attachTo : "bottom-right",
     map : myMap,
     color : "#FF0000",
     width : 200,
     height : 200,
     visible : true
    });
    //???????????
    overviewMap.startup();
    on(overviewMap, "onError", function(msg){
     console.log(msg);
    });
   });

   //?????????
   var scaleBar = new esri.dijit.Scalebar({
    map : myMap,
    attachTo : "bottom-left",
    scalebarUnit : "metric"
   });
   //scaleBar????startup()?????????????show()????????????????????
   scaleBar.show();

   //Define the geometry service that will be used to perform the buffer.
         var geometryService = new esri.tasks.GeometryService("http://192.168.1.142/ArcGIS/rest/services/Geometry/GeometryServer");

   //on(featureLayer, "mouse-over", function(evt) {
   on(featureLayer, "click", function(evt) {
    var result = dom.byId("result");
    var text = "<b>??????${name} ????ID??${osm_id}</b>";
    var content = esri.substitute(evt.graphic.attributes, text);
    result.innerHTML = content;
    myMap.graphics.clear();
    var params = new esri.tasks.BufferParameters();
    params.distances = [20, 30];
    params.unit = esri.tasks.GeometryService.UNIT_KILOMETER;
    params.outSpatialReference = myMap.spatialReference;
    params.geometries = [evt.mapPoint];
    //params.geometries = [evt.graphic.geometry];
    //??????????????
    geometryService.buffer(params,showBuffer);
    //???????????????????????????
    function showBuffer(geometries) {
     var sym = new esri.symbols.SimpleFillSymbol(esri.symbols.SimpleFillSymbol.STYLE_SOLID,
      new esri.symbols.SimpleLineSymbol(esri.symbols.SimpleLineSymbol.STYLE_SOLID,
       new dojo._base.Color([0, 255, 255, 0.65]), 2), new dojo._base.Color([0, 50, 255, 0.35]));
     //Array??"dojo/_base/array"
     Array.forEach(geometries, function(geo) {
      var gra = new esri.graphic(geo, sym, null, null);
      myMap.graphics.add(gra);
     });
    }
   });
});
    </script>
</head>

<body class="claro" style="height:100%;width:100%;margin:0;padding:0">
   <div data-dojo-type="dijit/layout/BorderContainer" data-dojo-props="design:'headline', gutters:false" style="width:100%;height:100%;margin:0;position:absolute">
    <div id="topNav" data-dojo-type="dijit/layout/ContentPane" data-dojo-props="region:'top'" style="height:30px;background-color:#777;">
     <p id="result"></p>
    </div>
    <div id="mapDiv" data-dojo-type="dijit/layout/ContentPane" data-dojo-props="region:'center'" style="padding:0">
     <div style="position:absolute;right:40px;top:30px;z-index:999">
      <div data-dojo-type="dijit/TitlePane" data-dojo-props="title:'?????????', closable:false, open:false">
       <div data-dojo-type="dijit/layout/ContentPane" style="width:380px;height:280px;overflow:auto;">
        <div id="baseMapGallery"></div>
       </div>
      </div>
     </div>
    </div>
   </div>
</body>
</html>

topic buffer analyst has non effect, here is my code, please help me in ArcGIS JavaScript Maps SDK Questions

buffer analyst has non effect, here is my code, please help me