js代码的框架如下：

代码如下:

var map;
var browserSupport = false;
var attempts = 0;
$(document).ready(function () {
//初始化地图
　　　　InitMap();
//定位
getLocation();
　　　　//定位跟踪
watchLocation();
});
function InitMap() {
/* Set all of the options for the map */
var options = {
};
/* Create a new Map for the application */
map = new google.maps.Map($('#map')[0], options);
}
/*
* If the W3C Geolocation object is available then get the current
* location, otherwise report the problem
*/
function getLocation() {
}
function watchLocation() {
}
/* Plot the location on the map and zoom to it */
function plotLocation(position) {
}
/* Report any errors using this function */
function reportProblem(e) {
}

InitMap方法就是调用google maps api初始化地图，他需要设置options对象，在调用地图初始化的时候使用。

代码如下:
function InitMap() {
/* Set all of the options for the map */
var options = {
zoom: 4,
center: new google.maps.LatLng(38.6201, -90.2003),
mapTypeId: google.maps.MapTypeId.ROADMAP,
mapTypeControl: true,
mapTypeControlOptions: {
style: google.maps.MapTypeControlStyle.HORIZONTAL_BAR,
position: google.maps.ControlPosition.BOTTOM_CENTER
},
panControl: true,
panControlOptions: {
position: google.maps.ControlPosition.TOP_RIGHT
},
zoomControl: true,
zoomControlOptions: {
style: google.maps.ZoomControlStyle.LARGE,
position: google.maps.ControlPosition.LEFT_CENTER
},
scaleControl: true,
scaleControlOptions: {
position: google.maps.ControlPosition.BOTTOM_LEFT
},
streetViewControl: true,
streetViewControlOptions: {
position: google.maps.ControlPosition.LEFT_TOP
}
};
/* Create a new Map for the application */
map = new google.maps.Map($('#map')[0], options);
}

getLocation和watchLocation方法获取定位信息。

代码如下:
function getLocation() {
/* Check if the browser supports the W3C Geolocation API */
if (navigator.geolocation) {
browserSupport = true;
navigator.geolocation.getCurrentPosition(plotLocation, reportProblem, { timeout: 45000 });
} else {
reportProblem();
}
}
function watchLocation() {
/* Check if the browser supports the W3C Geolocation API */
if (navigator.geolocation) {
browserSupport = true;
navigator.geolocation.watchPosition(plotLocation, reportProblem, { timeout: 45000 });
} else {
reportProblem();
}
}

成功获取位置信息后，调用plotLocation方法把位置显示在google maps上。

代码如下:
function plotLocation(position) {
attempts = 0;
var point = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
var marker = new google.maps.Marker({
position: point
});
marker.setMap(map);
map.setCenter(point);
map.setZoom(15);
}

demo下载地址：googleMapGeolocation.rar