WMS with Javascript API for ESRI

esri_map.js

var wmsAddress = "http://some.server.com/wms";
var map, srs, extent;

require(["esri/map",
         "esri/layers/WMSLayer",
         "esri/layers/WMSLayerInfo",
         "esri/geometry/Extent",
         "esri/geometry/Point",
         "esri/SpatialReference",
         "dojo/domReady!"],
        function (Map, WMSLayer, WMSLayerInfo, Extent, Point, SpatialReference) {

var wmsService = new WMSLayer(wmsAddress, {
    resourceInfo: {
        extent: extent,
        layerInfos: [new WMSLayerInfo({name:"layerName",title:"TestMap"})]
    },
    visibleLayers: ["layerName"]
});
wmsService.spatialReferences[0] = 900913;
map.addLayers([wmsService]);