var map;
function initialize() {
  var myLatLng = new google.maps.LatLng(nPosi,ePosi);
  var myOptions = {
    zoom: 18,
    center: myLatLng,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  }
  map = new google.maps.Map(document.getElementById("map"), myOptions);
  var zoomLevel;  
  var image = 'http://maps.google.co.jp/mapfiles/ms/icons/red-dot.png';
  
  var beachMarker = new google.maps.Marker({
      position: myLatLng,
      map: map,
      icon: image
  });
  google.maps.event.addListener(map, 'zoom_changed', function() {
    zoomLevel = map.get_zoom();
    map.setCenter(myLatLng);
    if (zoomLevel == 0) {
      map.setZoom(18);
    }
  });
}