I think there is some basic principle to the ArcGISDynamicMapServiceLayer's setVisibleLayers functionality that I am not undersanding and I'm hoping someone can tell me what I'm missing. Certainly, any of the forum posts I've found suggest that it works as I expect but I can't seem to affect the display of my map as I wish.I have created the example below to illustrate what I am trying to do in my application with my own data. Here, I am using servicesbeta1.esri.com's Water_Network service and setting the visible layers for the service to "MidScale" (19) and "Water Mains - Block View" (23). However, when I load the page, the map is also showing "Water Network Structures - City View" (layer 20). The circle with the letter 'T' is from that layer; and, as far as I am concerned, should not be displayed in the map given the setVisibleLayers([19,23]) call I am making. Can anyone tell me what I am missing here? Is there something else I'm supposed to do besides just pass an array identifying the visible layers I want shown? Cheers,jtm<html> <head> <title>setVisibleLayers Question</title> <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/dojo/dijit/themes/claro/claro.css"> <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/esri/css/esri.css" /> <script type="text/javascript" src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=3.2"></script> <script type="text/javascript"> dojo.require("esri.map"); function init() { var extent = new esri.geometry.Extent( { "xmin":1016752.0585392233,"ymin":1857876.6670321897,"xmax":1051557.2503922875,"ymax":1876696.1114766342 ,"spatialReference":{ "wkt": "PROJCS[\"NAD_1983_HARN_StatePlane_Illinois_East_FIPS_1201\",GEOGCS[\"GCS_North_American_1983_HARN\",DATUM[\"D_North_American_1983_HARN\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Transverse_Mercator\"],PARAMETER[\"False_Easting\",984250.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",-88.33333333333333],PARAMETER[\"Scale_Factor\",0.999975],PARAMETER[\"Latitude_Of_Origin\",36.66666666666666],UNIT[\"Foot_US\",0.3048006096012192]]" } } ); var map = new esri.Map("map",{extent: extent}); var service = new esri.layers.ArcGISDynamicMapServiceLayer("http://servicesbeta2.esri.com/arcgis/rest/services/Water_Network/MapServer"); // I've tried setting the visibleLayers before and after adding the ArcGISDynamicMapServiceLayer to the map // Here, I also tried the optional "false" to refresh, even though I hadn't added it to the map yet //service.setVisibleLayers([19,23]); map.addLayer(service); service.setVisibleLayers([19,23], false); } dojo.addOnLoad(init); </script> </head> <body> <div id="map" class="claro" style="width:1130px; height:611px; border:1px solid #000;"></div> </body> </html>