JSFiddle - React, Tailwind, and code Playground
HTML
<head>
<script src="http://maps.google.com/maps/api/js?v=3&sensor=false"></script>
<script src="http://www.openlayers.org/api/OpenLayers.js"></script>
</head>
<body>
<div id="map"></div>
</body>
CSS
#map{
position:absolute;
top:5px;
left:5px;
bottom:5px;
right:5px;
border:1px solid black;
}
JavaScript
var map;
map = new OpenLayers.Map({
div: "map",
projection: new OpenLayers.Projection("EPSG:900913")
});
var osm = new OpenLayers.Layer.OSM();
var gmap = new OpenLayers.Layer.Google("Google Streets");
var graphic = new OpenLayers.Layer.Image('City Lights', 'http://mapping.referata.com/w/images/4_m_citylights_lg.gif', new OpenLayers.Bounds(8.098224, 45.772682, 17.74378, 49.478924).transform(
new OpenLayers.Projection("EPSG:4326"), new OpenLayers.Projection("EPSG:900913")), new OpenLayers.Size(580, 288), {
isBaseLayer: false,
opacity: 0.5
});
map.addLayers([osm, gmap, graphic]);
map.addControl(new OpenLayers.Control.LayerSwitcher());
map.setCenter(
new OpenLayers.LonLat(13.2, 46.9).transform(
new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject()), 7);