var geocoder;
  var map;
  function initialize() {
    geocoder = new google.maps.Geocoder();
    var latlng = new google.maps.LatLng(-34.397, 150.644);
    var myOptions = {
      zoom: 15,
      center: latlng,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    }
    map = new google.maps.Map(document.getElementById("polohaMapa"), myOptions);
  }

  function codeAddress() {
    var address = document.getElementById("adresaMapa").value;
    if (address != '') {
        geocoder.geocode({ 'address': address }, function(results, status) {
            if (status == google.maps.GeocoderStatus.OK) {
                map.setCenter(results[0].geometry.location);
                var marker = new google.maps.Marker({
                    map: map,
                    position: results[0].geometry.location
                });
            } else {
                document.getElementById("polohaMapa").style.display = "none";
                //alert("Chyba mapy: " + status + ' ' + address);
            }
        });
    }
  }