var imageParameters = new esri.layers.ImageParameters(); imageParameters.layerIds = [1]; imageParameters.layerOption = esri.layers.ImageParameters.LAYER_OPTION_SHOW; polylineMLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://www.address_of_your_REST_service/MapServer", { "imageParameters": imageParameters, id: "polylineMLayer" }); map.addLayer(polylineMLayer);