Hi, You can use esri.show() and esri.hide() to add a splash screen.Here is a simple code sample which demonstrates the same:<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=7" />
<title>Splash Screen</title>
<link rel="stylesheet" href="https://community.esri.com//serverapi.arcgisonline.com/jsapi/arcgis/3.5/js/dojo/dijit/themes/tundra/tundra.css">
<link rel="stylesheet" href="https://community.esri.com//serverapi.arcgisonline.com/jsapi/arcgis/3.5/js/esri/css/esri.css">
<style type="text/css">
html, body
{
height: 100%;
width: 100%;
margin: 0;
padding: 0px;
font-family: helvetica, arial, sans-serif;
font-size: 90%;
}
#mapDiv
{
margin: 0px;
border: solid 1px #B5BCC7;
height: 100%;
width: 100%;
}
</style>
<script>var dojoConfig = { parseOnLoad: true };</script>
<script src="//serverapi.arcgisonline.com/jsapi/arcgis/3.5/"></script>
<script>
dojo.require("dijit.layout.BorderContainer");
dojo.require("dijit.layout.ContentPane");
dojo.require("esri.map");
dojo.require("esri.layers.FeatureLayer");
dojo.require("esri.IdentityManager");
dojo.require("esri.IdentityManagerBase");
var map;
function init() {
map = new esri.Map("mapCanvas",{
center: [-107.394, 37.563],
zoom: 9
});
esri.show(splashScreen);
var basemap = new esri.layers.ArcGISTiledMapServiceLayer("http://services.arcgisonline.com/ArcGIS/rest/services/USA_Topo_Maps/MapServer");
map.addLayer(basemap);
dojo.connect(map, "onLoad", function() {
//esri.hide(splashScreen);
});
}
function hideSplash(){
esri.hide(splashScreen);
map.resize();
map.reposition();
}
dojo.ready(init);
</script>
</head>
<body class="tundra">
<div data-dojo-type="dijit.layout.BorderContainer" data-dojo-props="design:'headline',gutters:false" style="position:relative;width:100%;height:100%;">
<div id="mapCanvas" data-dojo-type="dijit.layout.ContentPane" data-dojo-props="region:'center'" style="height:900px;">
<div data-dojo-type="dijit/Dialog" id="splashScreen" title="Welcome" style="position: absolute; top: 300px; left: 400px; z-index: 100;width:600px">
<table class="dijitDialogPaneContentArea">
<tr>
<td>
<div id="divDialogMessage">This is the splash text</div>
</td>
</tr>
</table>
<div class="dijitDialogPaneActionBar">
<button id="buttonClose" data-dojo-type="dijit/form/Button" type="button" style="align-content: center" onclick="hideSplash();">Close</button>
</div>
</div>
</div>
</div>
</body>
</html>
Please let me know if it helps!Thanks,Shreyas