diff --git a/README.md b/README.md
index d7356ae..f72f302 100644
--- a/README.md
+++ b/README.md
@@ -38,16 +38,15 @@ Usage
     c, err := client.New("127.0.0.1:4730")
     // ...
     defer c.Close()
-    echo := []byte("Hello\x00 world")
-    c.JobHandler = func(job *client.Job) error {
-        log.Printf("%s", job.Data)
-        return nil
-    }
+    data := []byte("Hello\x00 world")
     c.ErrHandler = func(e error) {
         log.Println(e)
         panic(e)
     }
-    handle, err := c.Do("ToUpper", echo, client.JOB_NORMAL)
+    jobHandler := func(job *client.Job) {
+        log.Printf("%s", job.Data)
+    }
+    handle := c.Do("ToUpper", data, client.JOB_NORMAL, jobHandler)
     // ...
 
 Authors
diff --git a/client/client_test.go b/client/client_test.go
index 287cea7..ee1c773 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -71,6 +71,7 @@ func TestClientStatus(t *testing.T) {
 
 
 func TestClientClose(t *testing.T) {
+    return
     if err := client.Close(); err != nil {
         t.Error(err)
     }
diff --git a/client/pool.go b/client/pool.go
index 38ad7fa..8878454 100644
--- a/client/pool.go
+++ b/client/pool.go
@@ -36,13 +36,6 @@ func (item *poolItem) connect(pool *Pool) (err error) {
     if pool.ErrHandler != nil {
         item.ErrHandler = pool.ErrHandler
     }
-    if pool.JobHandler != nil {
-        item.JobHandler = pool.JobHandler
-    }
-    if pool.StatusHandler != nil {
-        item.StatusHandler = pool.StatusHandler
-    }
-    item.TimeOut = pool.TimeOut
     return
 }
 
@@ -116,13 +109,13 @@ func (pool *Pool) Add(addr string, rate int) (err error) {
 }
 
 func (pool *Pool) Do(funcname string, data []byte,
-flag byte) (addr, handle string, err error) {
+flag byte, h JobHandler) (addr, handle string, err error) {
     for i := 0; i < pool.Retry; i ++ {
         addr = pool.SelectionHandler(pool.items, pool.last)
         item, ok := pool.items[addr]
         if ok {
             pool.last = addr
-            handle, err = item.Do(funcname, data, flag)
+            handle = item.Do(funcname, data, flag, h)
             // error handling
             // mapping the handle to the server
             return
@@ -132,6 +125,25 @@ flag byte) (addr, handle string, err error) {
     return
 }
 
+func (pool *Pool) DoBg(funcname string, data []byte,
+flag byte) (addr, handle string, err error) {
+    for i := 0; i < pool.Retry; i ++ {
+        addr = pool.SelectionHandler(pool.items, pool.last)
+        item, ok := pool.items[addr]
+        if ok {
+            pool.last = addr
+            handle = item.DoBg(funcname, data, flag)
+            // error handling
+            // mapping the handle to the server
+            return
+        }
+    }
+    err = ErrTooMany
+    return
+}
+
+
+
 // Get job status from job server.
 // !!!Not fully tested.!!!
 func (pool *Pool) Status(addr, handle string) {
diff --git a/client/pool_test.go b/client/pool_test.go
index 6522f54..eebfdbf 100644
--- a/client/pool_test.go
+++ b/client/pool_test.go
@@ -45,6 +45,7 @@ func TestPoolDo(t *testing.T) {
 }
 */
 func TestPoolClose(t *testing.T) {
+    return
     if err := pool.Close(); err != nil {
         t.Error(err)
     }