diff --git a/event/events.go b/event/events.go
index 016a17c..eae2d40 100644
--- a/event/events.go
+++ b/event/events.go
@@ -1,34 +1,39 @@
 // Copyright (c) 2014, B3log
-//  
+//
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
-//  
+//
 //     http://www.apache.org/licenses/LICENSE-2.0
-//  
+//
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Event manipulations.
+// Package event includes event related manipulations.
 package event
 
 import "github.com/golang/glog"
 
 const (
-	EvtCodeGOPATHNotFound      = iota // event code: not found $GOPATH env variable
-	EvtCodeGOROOTNotFound             // event code: not found $GOROOT env variable
-	EvtCodeGocodeNotFound             // event code: not found gocode
-	EvtCodeIDEStubNotFound            // event code: not found ide_stub
-	EvtCodeServerInternalError        // event code: server internal error
+	// EvtCodeGOPATHNotFound indicates an event: not found $GOPATH env variable
+	EvtCodeGOPATHNotFound = iota
+	// EvtCodeGOROOTNotFound indicates an event: not found $GOROOT env variable
+	EvtCodeGOROOTNotFound
+	// EvtCodeGocodeNotFound indicates an event: not found gocode
+	EvtCodeGocodeNotFound
+	// EvtCodeIDEStubNotFound indicates an event: not found ide_stub
+	EvtCodeIDEStubNotFound
+	// EvtCodeServerInternalError indicates an event: server internal error
+	EvtCodeServerInternalError
 )
 
 // Max length of queue.
-const MaxQueueLength = 10
+const maxQueueLength = 10
 
-// Event.
+// Event represents an event.
 type Event struct {
 	Code int         `json:"code"` // event code
 	Sid  string      `json:"sid"`  // wide session id related
@@ -38,21 +43,21 @@ type Event struct {
 // Global event queue.
 //
 // Every event in this queue will be dispatched to each user event queue.
-var EventQueue = make(chan *Event, MaxQueueLength)
+var EventQueue = make(chan *Event, maxQueueLength)
 
-// User event queue.
+// UserEventQueue represents a user event queue.
 type UserEventQueue struct {
 	Sid      string      // wide session id related
 	Queue    chan *Event // queue
 	Handlers []Handler   // event handlers
 }
 
-type Queues map[string]*UserEventQueue
+type queues map[string]*UserEventQueue
 
 // User event queues.
 //
 // <sid, *UserEventQueue>
-var UserEventQueues = Queues{}
+var UserEventQueues = queues{}
 
 // Load initializes the event handling.
 func Load() {
@@ -78,7 +83,7 @@ func (uq *UserEventQueue) AddHandler(handlers ...Handler) {
 }
 
 // New initializes a user event queue with the specified wide session id.
-func (ueqs Queues) New(sid string) *UserEventQueue {
+func (ueqs queues) New(sid string) *UserEventQueue {
 	q := ueqs[sid]
 	if nil != q {
 		glog.Warningf("Already exist a user queue in session [%s]", sid)
@@ -88,14 +93,14 @@ func (ueqs Queues) New(sid string) *UserEventQueue {
 
 	q = &UserEventQueue{
 		Sid:   sid,
-		Queue: make(chan *Event, MaxQueueLength),
+		Queue: make(chan *Event, maxQueueLength),
 	}
 
 	ueqs[sid] = q
 
 	go func() { // start listening
 		for evt := range q.Queue {
-			glog.V(5).Infof("Session [%s] received a event [%d]", sid, evt.Code)
+			glog.V(5).Infof("Session [%s] received an event [%d]", sid, evt.Code)
 
 			// process event by each handlers
 			for _, handler := range q.Handlers {
@@ -108,7 +113,7 @@ func (ueqs Queues) New(sid string) *UserEventQueue {
 }
 
 // Close closes a user event queue with the specified wide session id.
-func (ueqs Queues) Close(sid string) {
+func (ueqs queues) Close(sid string) {
 	q := ueqs[sid]
 	if nil == q {
 		return
@@ -117,15 +122,15 @@ func (ueqs Queues) Close(sid string) {
 	delete(ueqs, sid)
 }
 
-// Type of event handler.
+// Handler represents an event handler.
 type Handler interface {
 	Handle(event *Event)
 }
 
 // Type of handler function.
-type HandleFunc func(event *Event)
+type handleFunc func(event *Event)
 
 // Default implementation of event handling.
-func (fn HandleFunc) Handle(event *Event) {
+func (fn handleFunc) Handle(event *Event) {
 	fn(event)
 }