From 2014.igem.org
var map, layer;
function init(){
map = new OpenLayers.Map("map");
map.addLayer(new OpenLayers.Layer.OSM());
var lonLat = new OpenLayers.LonLat( -0.1279688 ,51.5077286 )
.transform(
new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
map.getProjectionObject() // to Spherical Mercator Projection
);
var zoom=16;
var markers = new OpenLayers.Layer.Markers( "Markers" );
map.addLayer(markers);
markers.addMarker(new OpenLayers.Marker(lonLat));
map.setCenter (lonLat, zoom);
}