function visualizzamappa(){
   geocoder = new google.maps.Geocoder();
   var myLatlng = new google.maps.LatLng(41.871132,12.454501);
    var myOptions = {
        zoom: 11,
        //center: myLatlng,
        mapTypeId: google.maps.MapTypeId.ROADMAP,
        mapTypeControl: false,
        streetViewControl: false   
    }
    var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
    
  var address = "piazza della Costituzione, 40127,Bologna";
  geocoder.geocode( { 'address': address}, function(results, status) {
    if (status == google.maps.GeocoderStatus.OK) {
      map.setCenter(results[0].geometry.location);
	  var infowindow = new google.maps.InfoWindow({
        content: "<strong>Sana</strong><br>piazza della Costituzione<br> 40127<br> Bologna",
        maxWidth:400
      });
      var marker = new google.maps.Marker({
          map: map,
          title: "Sana",
          position: results[0].geometry.location
      });
      //alert('Lat :' + marker.position.lat() + ' Lon :' + marker.position.lng());
   	  google.maps.event.addListener(marker, 'click', function() {
        infowindow.open(map,marker);
      });	  
    } else {
      alert('Geocode was not successful for the following reason: ' + status);
    }
  });
}