diff --git a/client/pool.go b/client/pool.go
index 9c5e643..03831b0 100644
--- a/client/pool.go
+++ b/client/pool.go
@@ -7,6 +7,7 @@ package client
 
 import (
     "sync"
+    "errors"
     "math/rand"
     "github.com/mikespook/gearman-go/common"
 )
@@ -15,6 +16,10 @@ const (
     PoolSize = 10
 )
 
+var (
+    ErrNotFound = errors.New("Server Not Found")
+)
+
 type poolClient struct {
     *Client
     Rate int
@@ -52,7 +57,10 @@ last string) (addr string) {
 type Pool struct {
     SelectionHandler SelectionHandler
     ErrHandler common.ErrorHandler
+
     clients map[string]*poolClient
+    last string
+
     mutex sync.Mutex
 }
 
@@ -90,25 +98,45 @@ func (pool *Pool) Remove(addr string) {
 }
 
 func (pool *Pool) Do(funcname string, data []byte,
-flag byte, h JobHandler) (handle string, err error) {
+flag byte, h JobHandler) (addr, handle string) {
+    client := pool.selectServer()
+    handle = client.Do(funcname, data, flag, h)
+    addr = client.addr
     return
 }
 
 func (pool *Pool) DoBg(funcname string, data []byte,
-flag byte) (handle string, err error) {
+flag byte) (addr, handle string) {
+    client := pool.selectServer()
+    handle = client.DoBg(funcname, data, flag)
+    addr = client.addr
     return
 }
 
-
-
 // Get job status from job server.
 // !!!Not fully tested.!!!
-func (pool *Pool) Status(handle string) (status *Status) {
+func (pool *Pool) Status(addr, handle string) (status *Status, err error) {
+    if client, ok := pool.clients[addr]; ok {
+        status = client.Status(handle)
+    } else {
+        err = ErrNotFound
+    }
     return
 }
 
 // Send a something out, get the samething back.
-func (pool *Pool) Echo(data []byte) (r []byte) {
+func (pool *Pool) Echo(addr string, data []byte) (r []byte, err error) {
+    var client *poolClient
+    if addr == "" {
+        client = pool.selectServer()
+    } else {
+        var ok bool
+        if client, ok = pool.clients[addr]; !ok {
+            err = ErrNotFound
+            return
+        }
+    }
+    r = client.Echo(data)
     return
 }
 
@@ -120,3 +148,15 @@ func (pool *Pool) Close() (err map[string]error) {
     }
     return
 }
+
+func (pool *Pool) selectServer() (client *poolClient) {
+    for client == nil {
+        addr := pool.SelectionHandler(pool.clients, pool.last)
+        var ok bool
+        if client, ok = pool.clients[addr]; ok {
+            pool.last = addr
+            break
+        }
+    }
+    return
+}
diff --git a/client/pool_test.go b/client/pool_test.go
index 9c86bc8..bf21f0c 100644
--- a/client/pool_test.go
+++ b/client/pool_test.go
@@ -20,30 +20,84 @@ func TestPoolAdd(t *testing.T) {
         t.Errorf("2 servers expected, %d got.", len(pool.clients))
     }
 }
-/*
 
 func TestPoolEcho(t *testing.T) {
-    pool.JobHandler = func(job *Job) error {
-        echo := string(job.Data)
-        if echo == "Hello world" {
-            t.Log(echo)
-        } else {
-            t.Errorf("Invalid echo data: %s", job.Data)
-        }
-        return nil
+    echo, err := pool.Echo("", []byte("Hello world"))
+    if err != nil {
+        t.Error(err)
+        return
+    }
+    if string(echo) != "Hello world" {
+        t.Errorf("Invalid echo data: %s", echo)
+        return
+    }
+
+    _, err = pool.Echo("not exists", []byte("Hello world"))
+    if err != ErrNotFound {
+        t.Errorf("ErrNotFound expected, got %s", err)
+    }
+}
+
+func TestPoolDoBg(t *testing.T) {
+    if addr, handle := pool.DoBg("ToUpper", []byte("abcdef"),
+        JOB_LOW); handle == "" {
+        t.Error("Handle is empty.")
+    } else {
+        t.Log(addr, handle)
     }
-    pool.Echo([]byte("Hello world"))
 }
 
 func TestPoolDo(t *testing.T) {
-    if addr, handle, err := pool.Do("ToUpper", []byte("abcdef"), JOB_LOW|JOB_BG); err != nil {
-        t.Error(err)
+    jobHandler := func(job *Job) {
+        str := string(job.Data)
+        if str == "ABCDEF" {
+            t.Log(str)
+        } else {
+            t.Errorf("Invalid data: %s", job.Data)
+        }
+        return
+    }
+    if addr, handle := pool.Do("ToUpper", []byte("abcdef"),
+        JOB_LOW, jobHandler); handle == "" {
+        t.Error("Handle is empty.")
     } else {
-        t.Log(handle)
+        t.Log(addr, handle)
+    }
+}
+
+func TestPoolStatus(t *testing.T) {
+    s1, err := pool.Status("127.0.0.1:4730", "handle not exists")
+    if err != nil {
+        t.Error(err)
+        return
+    }
+    if s1.Known {
+        t.Errorf("The job (%s) shouldn't be known.", s1.Handle)
+    }
+    if s1.Running {
+        t.Errorf("The job (%s) shouldn't be running.", s1.Handle)
+    }
+
+    addr, handle := pool.Do("Delay5sec", []byte("abcdef"), JOB_LOW, nil);
+    s2, err := pool.Status(addr, handle)
+    if err != nil {
+        t.Error(err)
+        return
+    }
+
+    if !s2.Known {
+        t.Errorf("The job (%s) should be known.", s2.Handle)
+    }
+    if s2.Running {
+        t.Errorf("The job (%s) shouldn't be running.", s2.Handle)
+    }
+
+    _, err = pool.Status("not exists", "not exists")
+    if err != ErrNotFound {
+        t.Error(err)
     }
 }
 
-*/
 func TestPoolClose(t *testing.T) {
     return
     if err := pool.Close(); err != nil {