自定义和原始标记都显示谷歌地图 api v3

出于某种原因，我同时显示了两个标记.. http://picpaste.com/Screen_Shot_2013-10-02_at_10.55.41_AM-qKfxgyCO.png

整个事情周围还有一个盒子。任何想法为什么会出现这些？

var gmap;
function initialize() {
  var myLat = new google.maps.LatLng(33.991447,-84.09403);
  var mapOptions = {
    zoom: 13,
    center: myLat,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };
  var gmap = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
  var mapIcon = '../fw/img/map-marker-lowres.png';
  var infowindowContent ='<div class="mapbox"><p><strong>The Arena at Gwinnett Center</strong></p>' + '<p>6400 Sugarloaf Pkwy<br>Duluth, GA 30097<br>(770) 813-7500</p>' + '<a href="http://goo.gl/maps/g3cs0">> get driving directions</a></div>';
  var infowindow = new google.maps.InfoWindow({
    content: infowindowContent,
    maxWidth: 250,
  });
  var marker = new google.maps.Marker({
    position: myLat,
    icon: mapIcon,
    map: gmap
  });
      marker.setMap(gmap);
      infowindow.open(gmap,marker);
}