谷歌地图:无法让InfoWindow显示

我正在创建一个带有标记和信息窗口的地图。除了信息窗口,一切似乎都在工作。我也没看到萤火虫有什么错误。

var myOptions = {
    zoom: 15,
    mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map;
var geocoder;
var marker;
var infowindow;

function initialize() {
    geocoder = new google.maps.Geocoder();
    geocoder.geocode({'address': '327 5th St, West Palm Beach, FL 33401-3995'}, function(results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            myOptions.center = results[0].geometry.location;
            map = new google.maps.Map(document.getElementById('map_canvas'), myOptions);
            marker = new google.maps.Marker({
                map: map,
                position: results[0].geometry.location,
                title: 'Middle East Bakery & Grocery'
            });
            infowindow = new google.maps.InfoWindow({
                title: '<strong>Middle East Bakery &amp; Grocery</strong><br />327 5th St<br />West Palm Beach, FL 33401-3995'
            });
            infowindow.open(map, marker);
            google.maps.event.addListener(marker, 'click', function() {
                infowindow.open(map, marker);
            });
        } else {
            alert('Geocode was not successful for the following reason: ' + status);
        }
    });
}