Google maps 在我的谷歌地图代码中，我可以在哪里向方向添加旅行模式？

我有我的自定义地图工作的方向。然而，我希望添加我在谷歌开发者网站上发现的下拉列表，它允许选择“自行车”、“驾驶”、“交通”、“步行”

---

这是我调用函数的代码，我不知道它们在哪里：

var map;
var gdir;
var geocoder = null;
var addressMarker;

function initialize() {
  if (GBrowserIsCompatible()) {      
    map = new GMap2(document.getElementById("map_canvas"));
    gdir = new GDirections(map, document.getElementById("directions"));
    GEvent.addListener(gdir, "load", onGDirectionsLoad);
    GEvent.addListener(gdir, "error", handleErrors);

    setDirections(document.getElementById("fromAddress").value, document.getElementById("toAddress").value, "en_US");
  }
}

function setDirections(fromAddress, toAddress, locale) {
  gdir.load("from: " + fromAddress + " to: " + toAddress,
            { "locale": locale });
}

---

这是URL，我想我需要把它放在我所拥有的东西的某个地方

--我想我可以先用一种模式来测试它，比如“行走”。然后在下拉菜单生效后添加下拉菜单

=====================================

    function calcRoute() {
var selectedMode = document.getElementById('mode').value;
var request = {
  origin: haight,
  destination: oceanBeach,
  // Note that Javascript allows us to access the constant
  // using square brackets and a string value as its
  // "property."
  travelMode: google.maps.TravelMode[selectedMode]
};
directionsService.route(request, function(response, status) {
if (status == google.maps.DirectionsStatus.OK) {
  directionsDisplay.setDirections(response);
}
});
}

我在以下网址找到此网址：

=========================================

    function calcRoute() {
var selectedMode = document.getElementById('mode').value;
var request = {
  origin: haight,
  destination: oceanBeach,
  // Note that Javascript allows us to access the constant
  // using square brackets and a string value as its
  // "property."
  travelMode: google.maps.TravelMode[selectedMode]
};
directionsService.route(request, function(response, status) {
if (status == google.maps.DirectionsStatus.OK) {
  directionsDisplay.setDirections(response);
}
});
}

---

这是在上面的代码，我想使用它

---

travelMode:google.maps.travelMode[“行走”]

我想出来了。我正在尝试向v2添加v3特性/语法。啊！（拍了拍额头）