js获取用户的地理位置

<script type="text/javascript">
        $(document).ready(function () {
            if (navigator.geolocation) {
                navigator.geolocation.getCurrentPosition(showMap);               
            }
        });
        var showMap = function (position) {
            var weidu = position.coords.latitude;
            var jingdu = position.coords.longitude;
            var str = weidu + "," + jingdu;
            $.ajax({
                url: "http://maps.google.cn/maps/api/geocode/json?latlng=" + str + "&sensor=true&language=zh-CN",
                type: "post",
                async: false,
                success: function (result) {
                    var dataObj = eval(result);
                    var str = new Array("门牌号", "街道地址", "区", "市", "省", "国家");
                    for (var i = 0; i < str.length; i++) {
                        alert(str[i].toString()+":"+ dataObj.results[0].address_components[i].long_name);                       
                    }
                }
            });
        };
    </script>