function map_init(mapid) {
/* Determine and define renderer */
 var renderer =
  OpenLayers.Util.getParameters(
   window.location.href).renderer;
 renderer = (renderer) ? [renderer] :
  OpenLayers.Layer.Vector.prototype.renderers;

/* Bind OpenLayers to DOM object */
 window.map = new OpenLayers.Map(mapid, {
  maxExtent: extent,
  projection: spherMerc,
  displayProjection: epsg4326,
  maxResolution: 'auto',
  numZoomLevels: 14,
  units: 'm',
   controls : [
    new OpenLayers.Control.PanZoom(),
    new OpenLayers.Control.Navigation(
     {zoomWheelEnabled: false}),
    new OpenLayers.Control.LayerSwitcher()
   ]});

/* Create base map */
 var base = new OpenLayers.Layer.OSM("FreeX-Map",
   ["http://a.tile.openstreetmap.org/${z}/${x}/${y}.png",
   "http://b.tile.openstreetmap.org/${z}/${x}/${y}.png",
   "http://c.tile.openstreetmap.org/${z}/${x}/${y}.png"],
   {
    wrapDateLine: false,
    isBaseLayer: true,
    displayOutsideMaxExtend: true,
    tileOptions: {crossOriginKeyword: null}
   });
/* Create layers and bind base map & DOM object */
 freex = map_layer(window.map, "FreeX-Layer (normal)");
 freex_o_r_p = map_layer_request_post(window.map,
  "FreeX-Layer (POST-Request)");
freex_l_h_s = map_layer_http_strategy (window.map,
  "FreeX-Layer (HTTP und Strategy)");
 if (base && freex && freex_o_r_p && freex_l_h_s) {
  window.map.addLayers(
   [base, freex, freex_o_r_p, freex_l_h_s]);
 }
/* Center map and define zoom factor */
 window.map.setCenter(
  new OpenLayers.LonLat(11, 48).
   transform(epsg4326, spherMerc), 9);
}