function setup()
    {
        // Create the map, passing in the name of the div in which we want the
        // map to be displayed
        var map = new OpenLayers.Map('map');
        // Create a Web Mapping Service layer to provide map imagery
        var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS", 
            "http://labs.metacarta.com/wms-c/Basic.py?", {layers: 'basic'} );
        // Add a second WMS layer containing a physical map
        var wms2 = new OpenLayers.Layer.WMS( "Blue Marble", 
            "http://labs.metacarta.com/wms-c/Basic.py?", {layers: 'satellite' } );
        // Add a GeoRSS dataset as an overlay
        var georss = new OpenLayers.Layer.GeoRSS( "GeoRSS layer", "/header/marine_obs.georss");
        // Add the layers to the map
        map.addLayers([wms, wms2, georss]);
        // Create a LayerSwitcher control
        map.addControl(new OpenLayers.Control.LayerSwitcher());
        // Display the whole globe
        map.zoomToMaxExtent();
    }