var title   = "分享百度";
    var img_url = "http://g.hiphotos.baidu.com/baike/c0%3Dbaike80%2C5%2C5%2C80%2C26/sign=aea27efc67380cd7f213aabfc02dc651/a5c27d1ed21b0ef405091912dfc451da80cb3e9c.jpg";
    var link    = "http://www.baidu.com";
    var desc    = "把分享链接改为百度地址";
    
    document.addEventListener(‘WeixinJSBridgeReady‘, function onBridgeReady() {
                              // 发送给好友
                              WeixinJSBridge.on(‘menu:share:appmessage‘, function (argv) {
                                                WeixinJSBridge.invoke(‘sendAppMessage‘, {
                                                                      "appid": "123",
                                                                      "img_url": img_url,
                                                                      "img_width": "160",
                                                                      "img_height": "160",
                                                                      "link": link,
                                                                      "desc":  desc,
                                                                      "title": title
                                                                      }, function (res) {
                                                                      _report(‘send_msg‘, res.err_msg);
                                                                      })
                                                });
                              
                              // 分享到朋友圈
                              WeixinJSBridge.on(‘menu:share:timeline‘, function (argv) {
                                                WeixinJSBridge.invoke(‘shareTimeline‘, {
                                                                      "img_url":img_url,
                                                                      "img_width": "160",
                                                                      "img_height": "160",
                                                                      "link": link,
                                                                      "desc":  desc,
                                                                      "title": title
                                                                      }, function (res) {
                                                                      _report(‘timeline‘, res.err_msg);
                                                                      });
                                                });
                              }, false)

 <input type="button" value="关闭本窗口" onclick="WeixinJSBridge.call(‘closeWindow‘);" />