var map=null;

function initialize(latitude,longitude,idcanvas,zoom) {
    var latlng = new google.maps.LatLng(latitude, longitude);
    var myOptions = {
      zoom: 8,
      center: latlng,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    
    //myOptions.zoom=zoom;

    map = new google.maps.Map(document.getElementById(idcanvas),
        myOptions);

    //map.MapOptions.zoom =zoom;
    map.setZoom(zoom);

    
    var marker = new google.maps.Marker({
      position: latlng,
      map: map,
      title:"Hello World!"
  });

        
}

function setmarker(latitude,longitude,zoom) {

  var latlng = new google.maps.LatLng(latitude, longitude);
  var marker = new google.maps.Marker({
      position: latlng,
      map: map,
      title:"Hello World!"
   });
   map.setZoom(zoom);
}