Drop Google Maps markers when the Map scrolls into view

	function isMapScrolledIntoView(elem)
	{
	    var $elem = $(elem);
	    var $window = $(window);

	    var docViewTop = $window.scrollTop();
	    var docViewBottom = docViewTop + $window.height();

	    var elemTop = $elem.offset().top;
	    var elemBottom = elemTop + $elem.height();

	    return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
	}
	function initialize() {
	    var styles = [{"featureType":"all","elementType":"all","stylers":[{"saturation":-100},{"gamma":0.5}]}];
		var options = {
		    mapTypeControlOptions: {
		        mapTypeIds: ['Styled']
		    },
		    center: new google.maps.LatLng(51.524498, -0.078920),
		    zoom: 12,
		    scrollwheel: false,
		    disableDefaultUI: true,
		    navigationControl: false,
		    mapTypeControl: false,
		    scaleControl: false,
		    draggable: true,
		    mapTypeId: 'Styled'
		};
		var contentString = '<div id="content">' +
		      '<h3 id="heading">wplap</h3>' +
		      '<h3>The WordPress Code Express</h3>' +
		      '</div>';


		var div = document.getElementById('et-google-map-area');
		var map = new google.maps.Map(div, options);
		var styledMapType = new google.maps.StyledMapType(styles, {
		    name: 'Styled'
		});
		map.mapTypes.set('Styled', styledMapType);
		var marker = new google.maps.Marker({
		    position: new google.maps.LatLng(51.524498, -0.078920),
		    map: map,
		    icon: null,
		});
		var infowindow = new google.maps.InfoWindow({
		    content: contentString,
		    maxWidth: 280
		});
		var fired = 0;
		$(window).scroll(function() {
			if(fired == 0){
				if (isMapScrolledIntoView('#et-google-map-view')) {
					marker.setAnimation(google.maps.Animation.DROP);
					marker.setIcon("http://i.imgur.com/zORV1Ud.png");
					fired = 1;
					console.log('one time only')
				}
			}
		});
		google.maps.event.addListener(marker, 'click', function () {
		    infowindow.open(map, marker);
		});
	}

	google.maps.event.addDomListener(window, 'load', initialize);