var mapa;
  var tip;

  function mapaStart() {
    if(GBrowserIsCompatible()) {
      mapa = new GMap2(document.getElementById("map_container"));
      mapa.setCenter(new GLatLng(51.6834984,16.111291700000038),13);
      mapa.addControl(new GLargeMapControl());
      mapa.addControl(new GScaleControl());
      mapa.addControl(new GMapTypeControl());
      mapa.enableDoubleClickZoom();
      mapa.enableContinuousZoom();
      mapa.enableScrollWheelZoom();
      ico1 = new GIcon();
      ico1.image = "https://www.bazakoni.pl/img/mapa/4.png";
      ico1.shadow = "https://www.bazakoni.pl/img/mapa/shadow.png";
      ico1.iconSize = new GSize(21,31);
      ico1.infoWindowAnchor = new GPoint(10,35);
      ico1.iconAnchor = new GPoint(10,31);
      ico1.shadowSize = new GSize(37,31);
      var m = new GMarker(new GLatLng(51.6834984,16.111291700000038), 
              {title:'Serby, Polska', icon:ico1});
      mapa.addOverlay(m);
      GEvent.addListener(m,"click",function() {
        mapa.setZoom(13);
        mapa.panTo(m.getLatLng());
        m.openInfoWindowHtml(tip);
        });
      m.openInfoWindowHtml(tip);
    }
  }

  var oldonload = window.onload;
  if (typeof window.onload != "function"){
    window.onload = mapaStart;
  } else {
    window.onload = function(){
      oldonload();
      mapaStart();
    }
  }