diff --git a/bot_test.go b/bot_test.go
index 66d1eaf..40d87f0 100644
--- a/bot_test.go
+++ b/bot_test.go
@@ -3,6 +3,7 @@ package openwechat
 import (
     "fmt"
     "testing"
+    "time"
 )
 
 func defaultBot(modes ...mode) *Bot {
@@ -189,6 +190,7 @@ func TestSendMessage(t *testing.T) {
         t.Error(err)
         return
     }
+    time.Sleep(time.Second)
     if err = self.SendTextToFriend(helper, "send test message twice ! received?"); err != nil {
         t.Error(err)
         return
diff --git a/message.go b/message.go
index 84e6d7c..6c61711 100644
--- a/message.go
+++ b/message.go
@@ -1,270 +1,271 @@
 package openwechat
 
 import (
-    "context"
-    "encoding/xml"
-    "errors"
-    "net/http"
-    "os"
-    "strings"
-    "sync"
-    "time"
-    "unicode"
+	"context"
+	"encoding/xml"
+	"errors"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+	"unicode"
 )
 
 type Message struct {
-    IsAt    bool
-    AppInfo struct {
-        Type  int
-        AppID string
-    }
-    AppMsgType            int
-    HasProductId          int
-    ImgHeight             int
-    ImgStatus             int
-    ImgWidth              int
-    ForwardFlag           int
-    MsgType               int
-    Status                int
-    StatusNotifyCode      int
-    SubMsgType            int
-    VoiceLength           int
-    CreateTime            int64
-    NewMsgId              int64
-    PlayLength            int64
-    MediaId               string
-    MsgId                 string
-    EncryFileName         string
-    FileName              string
-    FileSize              string
-    Content               string
-    FromUserName          string
-    OriContent            string
-    StatusNotifyUserName  string
-    Ticket                string
-    ToUserName            string
-    Url                   string
-    senderInGroupUserName string
-    RecommendInfo         RecommendInfo
-    Bot                   *Bot
-    mu                    sync.RWMutex
-    Context               context.Context
-    item                  map[string]interface{}
+	IsAt    bool
+	AppInfo struct {
+		Type  int
+		AppID string
+	}
+	AppMsgType            int
+	HasProductId          int
+	ImgHeight             int
+	ImgStatus             int
+	ImgWidth              int
+	ForwardFlag           int
+	MsgType               int
+	Status                int
+	StatusNotifyCode      int
+	SubMsgType            int
+	VoiceLength           int
+	CreateTime            int64
+	NewMsgId              int64
+	PlayLength            int64
+	MediaId               string
+	MsgId                 string
+	EncryFileName         string
+	FileName              string
+	FileSize              string
+	Content               string
+	FromUserName          string
+	OriContent            string
+	StatusNotifyUserName  string
+	Ticket                string
+	ToUserName            string
+	Url                   string
+	senderInGroupUserName string
+	RecommendInfo         RecommendInfo
+	Bot                   *Bot
+	mu                    sync.RWMutex
+	Context               context.Context
+	item                  map[string]interface{}
 }
 
 // 获取消息的发送者
 func (m *Message) Sender() (*User, error) {
-    members, err := m.Bot.self.Members(true)
-    if err != nil {
-        return nil, err
-    }
-    if m.FromUserName == m.Bot.self.User.UserName {
-        return m.Bot.self.User, nil
-    }
-    user := members.SearchByUserName(1, m.FromUserName)
-    if user == nil {
-        return nil, noSuchUserFoundError
-    }
-    return user.First().Detail()
+	members, err := m.Bot.self.Members(true)
+	if err != nil {
+		return nil, err
+	}
+	if m.FromUserName == m.Bot.self.User.UserName {
+		return m.Bot.self.User, nil
+	}
+	user := members.SearchByUserName(1, m.FromUserName)
+	if user == nil {
+		return nil, noSuchUserFoundError
+	}
+	return user.First().Detail()
 }
 
 // 获取消息在群里面的发送者
 func (m *Message) SenderInGroup() (*User, error) {
-    if !m.IsSendByGroup() {
-        return nil, errors.New("message is not from group")
-    }
-    group, err := m.Sender()
-    if err != nil {
-        return nil, err
-    }
-    group, err = group.Detail()
-    if err != nil {
-        return nil, err
-    }
-    users := group.MemberList.SearchByUserName(1, m.senderInGroupUserName)
-    if users == nil {
-        return nil, noSuchUserFoundError
-    }
-    return users.First(), nil
+	if !m.IsSendByGroup() {
+		return nil, errors.New("message is not from group")
+	}
+	group, err := m.Sender()
+	if err != nil {
+		return nil, err
+	}
+	group, err = group.Detail()
+	if err != nil {
+		return nil, err
+	}
+	users := group.MemberList.SearchByUserName(1, m.senderInGroupUserName)
+	if users == nil {
+		return nil, noSuchUserFoundError
+	}
+	return users.First(), nil
 }
 
 // 获取消息的接收者
 func (m *Message) Receiver() (*User, error) {
-    if m.IsSendByGroup() {
-        if sender, err := m.Sender(); err != nil {
-            return nil, err
-        } else {
-            users := sender.MemberList.SearchByUserName(1, m.ToUserName)
-            if users == nil {
-                return nil, noSuchUserFoundError
-            }
-            return users.First(), nil
-        }
-    } else {
-        users := m.Bot.self.MemberList.SearchByUserName(1, m.ToUserName)
-        if users == nil {
-            return nil, noSuchUserFoundError
-        }
-        return users.First(), nil
-    }
+	if m.IsSendByGroup() {
+		if sender, err := m.Sender(); err != nil {
+			return nil, err
+		} else {
+			users := sender.MemberList.SearchByUserName(1, m.ToUserName)
+			if users == nil {
+				return nil, noSuchUserFoundError
+			}
+			return users.First(), nil
+		}
+	} else {
+		users := m.Bot.self.MemberList.SearchByUserName(1, m.ToUserName)
+		if users == nil {
+			return nil, noSuchUserFoundError
+		}
+		return users.First(), nil
+	}
 }
 
 // 判断消息是否由自己发送
 func (m *Message) IsSendBySelf() bool {
-    return m.FromUserName == m.Bot.self.User.UserName
+	return m.FromUserName == m.Bot.self.User.UserName
 }
 
 // 判断消息是否由好友发送
 func (m *Message) IsSendByFriend() bool {
-    return !m.IsSendByGroup() && strings.HasPrefix(m.FromUserName, "@")
+	return !m.IsSendByGroup() && strings.HasPrefix(m.FromUserName, "@")
 }
 
 // 判断消息是否由群组发送
 func (m *Message) IsSendByGroup() bool {
-    return strings.HasPrefix(m.FromUserName, "@@")
+	return strings.HasPrefix(m.FromUserName, "@@")
 }
 
 // 回复消息
 func (m *Message) Reply(msgType int, content, mediaId string) error {
-    msg := NewSendMessage(msgType, content, m.Bot.self.User.UserName, m.FromUserName, mediaId)
-    info := m.Bot.storage.LoginInfo
-    request := m.Bot.storage.Request
-    return m.Bot.Caller.WebWxSendMsg(msg, info, request)
+	msg := NewSendMessage(msgType, content, m.Bot.self.User.UserName, m.FromUserName, mediaId)
+	info := m.Bot.storage.LoginInfo
+	request := m.Bot.storage.Request
+	return m.Bot.Caller.WebWxSendMsg(msg, info, request)
 }
 
 // 回复文本消息
 func (m *Message) ReplyText(content string) error {
-    return m.Reply(TextMessage, content, "")
+	return m.Reply(TextMessage, content, "")
 }
 
 // 回复图片消息
 func (m *Message) ReplyImage(file *os.File) error {
-    info := m.Bot.storage.LoginInfo
-    request := m.Bot.storage.Request
-    return m.Bot.Caller.WebWxSendImageMsg(file, request, info, m.Bot.self.UserName, m.FromUserName)
+	info := m.Bot.storage.LoginInfo
+	request := m.Bot.storage.Request
+	return m.Bot.Caller.WebWxSendImageMsg(file, request, info, m.Bot.self.UserName, m.FromUserName)
 }
 
 func (m *Message) IsText() bool {
-    return m.MsgType == 1 && m.Url == ""
+	return m.MsgType == 1 && m.Url == ""
 }
 
 func (m *Message) IsMap() bool {
-    return m.MsgType == 1 && m.Url != ""
+	return m.MsgType == 1 && m.Url != ""
 }
 
 func (m *Message) IsPicture() bool {
-    return m.MsgType == 3 || m.MsgType == 47
+	return m.MsgType == 3 || m.MsgType == 47
 }
 
 func (m *Message) IsVoice() bool {
-    return m.MsgType == 34
+	return m.MsgType == 34
 }
 
 func (m *Message) IsFriendAdd() bool {
-    return m.MsgType == 37
+	return m.MsgType == 37
 }
 
 func (m *Message) IsCard() bool {
-    return m.MsgType == 42
+	return m.MsgType == 42
 }
 
 func (m *Message) IsVideo() bool {
-    return m.MsgType == 43 || m.MsgType == 62
+	return m.MsgType == 43 || m.MsgType == 62
 }
 
 func (m *Message) IsMedia() bool {
-    return m.MsgType == 49
+	return m.MsgType == 49
 }
 
 func (m *Message) IsRecalled() bool {
-    return m.MsgType == 10002
+	return m.MsgType == 10002
 }
 
 func (m *Message) IsSystem() bool {
-    return m.MsgType == 10000
+	return m.MsgType == 10000
 }
 
 func (m *Message) IsNotify() bool {
-    return m.MsgType == 51 && m.StatusNotifyCode != 0
+	return m.MsgType == 51 && m.StatusNotifyCode != 0
 }
 
 // 判断消息是否为文件类型的消息
 func (m *Message) HasFile() bool {
-    return m.IsPicture() || m.IsVoice() || m.IsVideo() || m.IsMedia()
+	return m.IsPicture() || m.IsVoice() || m.IsVideo() || m.IsMedia()
 }
 
 // 获取文件消息的文件
 func (m *Message) GetFile() (*http.Response, error) {
-    if !m.HasFile() {
-        return nil, errors.New("invalid message type")
-    }
-    if m.IsPicture() {
-        return m.Bot.Caller.Client.WebWxGetMsgImg(m, m.Bot.storage.LoginInfo)
-    }
-    if m.IsVoice() {
-        return m.Bot.Caller.Client.WebWxGetVoice(m, m.Bot.storage.LoginInfo)
-    }
-    if m.IsVideo() {
-        return m.Bot.Caller.Client.WebWxGetVideo(m, m.Bot.storage.LoginInfo)
-    }
-    if m.IsMedia() {
-        return m.Bot.Caller.Client.WebWxGetMedia(m, m.Bot.storage.LoginInfo)
-    }
-    return nil, errors.New("unsupported type")
+	if !m.HasFile() {
+		return nil, errors.New("invalid message type")
+	}
+	if m.IsPicture() {
+		return m.Bot.Caller.Client.WebWxGetMsgImg(m, m.Bot.storage.LoginInfo)
+	}
+	if m.IsVoice() {
+		return m.Bot.Caller.Client.WebWxGetVoice(m, m.Bot.storage.LoginInfo)
+	}
+	if m.IsVideo() {
+		return m.Bot.Caller.Client.WebWxGetVideo(m, m.Bot.storage.LoginInfo)
+	}
+	if m.IsMedia() {
+		return m.Bot.Caller.Client.WebWxGetMedia(m, m.Bot.storage.LoginInfo)
+	}
+	return nil, errors.New("unsupported type")
 }
 
 // 获取card类型
 func (m *Message) Card() (*Card, error) {
-    if !m.IsCard() {
-        return nil, errors.New("card message required")
-    }
-    var card Card
-    content := XmlFormString(m.Content)
-    err := xml.Unmarshal([]byte(content), &card)
-    return &card, err
+	if !m.IsCard() {
+		return nil, errors.New("card message required")
+	}
+	var card Card
+	content := XmlFormString(m.Content)
+	err := xml.Unmarshal([]byte(content), &card)
+	return &card, err
 }
 
 // 往消息上下文中设置值
 // goroutine safe
 func (m *Message) Set(key string, value interface{}) {
-    m.mu.Lock()
-    defer m.mu.Unlock()
-    if m.item == nil {
-        m.item = make(map[string]interface{})
-    }
-    m.item[key] = value
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if m.item == nil {
+		m.item = make(map[string]interface{})
+	}
+	m.item[key] = value
 }
 
 // 从消息上下文中获取值
 // goroutine safe
 func (m *Message) Get(key string) (value interface{}, exist bool) {
-    m.mu.RLock()
-    defer m.mu.RUnlock()
-    value, exist = m.item[key]
-    return
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	value, exist = m.item[key]
+	return
 }
 
 // 消息初始化,根据不同的消息作出不同的处理
 func (m *Message) init(bot *Bot) {
-    m.Bot = bot
-    if m.IsSendByGroup() {
-        data := strings.Split(m.Content, ":<br/>")
-        m.Content = strings.Join(data[1:], "")
-        m.senderInGroupUserName = data[0]
-        receiver, err := m.Receiver()
-        if err == nil {
-            displayName := receiver.DisplayName
-            if displayName == "" {
-                displayName = receiver.NickName
-            }
-            atFlag := "@" + displayName
-            index := len(atFlag) + 1 + 1
-            if strings.HasPrefix(m.Content, atFlag) && unicode.IsSpace(rune(m.Content[index])) {
-                m.IsAt = true
-                m.Content = m.Content[index+1:]
-            }
-        }
-    }
+	m.Bot = bot
+	if m.IsSendByGroup() {
+		data := strings.Split(m.Content, ":<br/>")
+		m.Content = strings.Join(data[1:], "")
+		m.senderInGroupUserName = data[0]
+		receiver, err := m.Receiver()
+		if err == nil {
+			displayName := receiver.DisplayName
+			if displayName == "" {
+				displayName = receiver.NickName
+			}
+			atFlag := "@" + displayName
+			index := len(atFlag) + 1 + 1
+			if strings.HasPrefix(m.Content, atFlag) && unicode.IsSpace(rune(m.Content[index])) {
+				m.IsAt = true
+				m.Content = m.Content[index+1:]
+			}
+		}
+	}
 }
 
 //func (m *Message) Agree() error {
@@ -276,76 +277,77 @@ func (m *Message) init(bot *Bot) {
 
 // 发送消息的结构体
 type SendMessage struct {
-    Type         int
-    Content      string
-    FromUserName string
-    ToUserName   string
-    LocalID      int64
-    ClientMsgId  int64
-    MediaId      string
+	Type         int
+	Content      string
+	FromUserName string
+	ToUserName   string
+	LocalID      string
+	ClientMsgId  string
+	MediaId      string
 }
 
 // SendMessage的构造方法
 func NewSendMessage(msgType int, content, fromUserName, toUserName, mediaId string) *SendMessage {
-    return &SendMessage{
-        Type:         msgType,
-        Content:      content,
-        FromUserName: fromUserName,
-        ToUserName:   toUserName,
-        LocalID:      time.Now().Unix() * 1e4,
-        ClientMsgId:  time.Now().Unix() * 1e4,
-        MediaId:      mediaId,
-    }
+	id := strconv.FormatInt(time.Now().Unix()*1e4, 10)
+	return &SendMessage{
+		Type:         msgType,
+		Content:      content,
+		FromUserName: fromUserName,
+		ToUserName:   toUserName,
+		LocalID:      id,
+		ClientMsgId:  id,
+		MediaId:      mediaId,
+	}
 }
 
 // 文本消息的构造方法
 func NewTextSendMessage(content, fromUserName, toUserName string) *SendMessage {
-    return NewSendMessage(TextMessage, content, fromUserName, toUserName, "")
+	return NewSendMessage(TextMessage, content, fromUserName, toUserName, "")
 }
 
 // 媒体消息的构造方法
 func NewMediaSendMessage(msgType int, fromUserName, toUserName, mediaId string) *SendMessage {
-    return NewSendMessage(msgType, "", fromUserName, toUserName, mediaId)
+	return NewSendMessage(msgType, "", fromUserName, toUserName, mediaId)
 }
 
 // 一些特殊类型的消息会携带该结构体信息
 type RecommendInfo struct {
-    Alias      string
-    AttrStatus int64
-    City       string
-    Content    string
-    NickName   string
-    OpCode     int
-    Province   string
-    QQNum      int64
-    Scene      int
-    Sex        int
-    Signature  string
-    Ticket     string
-    UserName   string
-    VerifyFlag int
+	OpCode     int
+	Scene      int
+	Sex        int
+	VerifyFlag int
+	AttrStatus int64
+	QQNum      int64
+	Alias      string
+	City       string
+	Content    string
+	NickName   string
+	Province   string
+	Signature  string
+	Ticket     string
+	UserName   string
 }
 
 // 名片消息内容
 type Card struct {
-    XMLName                 xml.Name `xml:"msg"`
-    BigHeadImgUrl           string   `xml:"bigheadimgurl,attr"`
-    SmallHeadImgUrl         string   `xml:"smallheadimgurl,attr"`
-    UserName                string   `xml:"username,attr"`
-    NickName                string   `xml:"nickname,attr"`
-    ShortPy                 string   `xml:"shortpy,attr"`
-    Alias                   string   `xml:"alias,attr"` // Note: 这个是名片用户的微信号
-    ImageStatus             int      `xml:"imagestatus,attr"`
-    Scene                   int      `xml:"scene,attr"`
-    Province                string   `xml:"province,attr"`
-    City                    string   `xml:"city,attr"`
-    Sign                    string   `xml:"sign,attr"`
-    Sex                     int      `xml:"sex,attr"`
-    Certflag                int      `xml:"certflag,attr"`
-    Certinfo                string   `xml:"certinfo,attr"`
-    BrandIconUrl            string   `xml:"brandIconUrl,attr"`
-    BrandHomeUr             string   `xml:"brandHomeUr,attr"`
-    BrandSubscriptConfigUrl string   `xml:"brandSubscriptConfigUrl,attr"`
-    BrandFlags              string   `xml:"brandFlags,attr"`
-    RegionCode              string   `xml:"regionCode,attr"`
+	XMLName                 xml.Name `xml:"msg"`
+	ImageStatus             int      `xml:"imagestatus,attr"`
+	Scene                   int      `xml:"scene,attr"`
+	Sex                     int      `xml:"sex,attr"`
+	Certflag                int      `xml:"certflag,attr"`
+	BigHeadImgUrl           string   `xml:"bigheadimgurl,attr"`
+	SmallHeadImgUrl         string   `xml:"smallheadimgurl,attr"`
+	UserName                string   `xml:"username,attr"`
+	NickName                string   `xml:"nickname,attr"`
+	ShortPy                 string   `xml:"shortpy,attr"`
+	Alias                   string   `xml:"alias,attr"` // Note: 这个是名片用户的微信号
+	Province                string   `xml:"province,attr"`
+	City                    string   `xml:"city,attr"`
+	Sign                    string   `xml:"sign,attr"`
+	Certinfo                string   `xml:"certinfo,attr"`
+	BrandIconUrl            string   `xml:"brandIconUrl,attr"`
+	BrandHomeUr             string   `xml:"brandHomeUr,attr"`
+	BrandSubscriptConfigUrl string   `xml:"brandSubscriptConfigUrl,attr"`
+	BrandFlags              string   `xml:"brandFlags,attr"`
+	RegionCode              string   `xml:"regionCode,attr"`
 }