diff --git a/trunk/module/task/control.php b/trunk/module/task/control.php
index e613783774..ac1066579f 100644
--- a/trunk/module/task/control.php
+++ b/trunk/module/task/control.php
@@ -162,6 +162,8 @@ class task extends control
     {
         $this->loadModel('action');
         $task = $this->task->getById($taskID);
+        if(!$task) die(js::error($this->lang->notFound) . js::locate('back'));
+
         $project = $this->project->getById($task->project);
 
         /* 设置菜单。*/
@@ -198,8 +200,10 @@ class task extends control
         }
         else
         {
-            $this->task->delete($taskID);
-            die(js::locate($this->createLink('project', 'browse', "projectID=$projectID"), 'parent'));
+            $story = $this->dao->select('story')->from(TABLE_TASK)->where('id')->eq($taskID)->fetch('story');
+            $this->task->delete(TABLE_TASK, $taskID);
+            if($story) $this->loadModel('story')->setStage($story);
+            die(js::locate($this->session->taskList, 'parent'));
         }
     }
 
diff --git a/trunk/module/task/model.php b/trunk/module/task/model.php
index ef651f9c38..c7f37ae49b 100644
--- a/trunk/module/task/model.php
+++ b/trunk/module/task/model.php
@@ -87,15 +87,6 @@ class taskModel extends model
         if(!dao::isError()) return common::createChanges($oldTask, $task);
     }
     
-    /* 删除一个任务。*/
-    public function delete($taskID)
-    {
-        $story = $this->dao->select('*')->from(TABLE_TASK)->where('id')->eq($taskID)->fetch('story');
-        $this->dao->delete()->from(TABLE_TASK)->where('id')->eq((int)$taskID)->limit(1)->exec();
-        if($story) $this->loadModel('story')->setStage($story);
-        return;
-    }
-
     /* 通过id获取一个任务信息。*/
     public function getById($taskID)
     {
@@ -124,6 +115,7 @@ class taskModel extends model
             ->leftJoin(TABLE_USER)->alias('t3')
             ->on('t1.owner = t3.account')
             ->where('t1.project')->eq((int)$projectID)
+            ->andWhere('t1.deleted')->eq(0)
             ->onCaseOf($status == 'needConfirm')->andWhere('t2.version > t1.storyVersion')->andWhere("t2.status = 'active'")->endCase()
             ->onCaseOf($status != 'all' and $status != 'needConfirm')->andWhere('t1.status')->in($status)->endCase()
             ->andWhere('t3.company')->eq($this->app->company->id)
@@ -143,6 +135,7 @@ class taskModel extends model
             ->leftJoin(TABLE_USER)->alias('t2')
             ->on('t1.owner = t2.account')
             ->where('t1.project')->eq((int)$projectID)
+            ->andWhere('t1.deleted')->eq(0)
             ->onCaseOf($status != 'all')->andWhere('t1.status')->in($status)->endCase()
             ->andWhere('t2.company')->eq($this->app->company->id)
             ->orderBy($orderBy)
@@ -161,6 +154,7 @@ class taskModel extends model
             ->leftjoin(TABLE_STORY)->alias('t3')
             ->on('t1.story = t3.id')
             ->where('t1.owner')->eq($account)
+            ->andWhere('t1.deleted')->eq(0)
             ->onCaseOf($status != 'all')->andWhere('t1.status')->in($status)->endCase()
             ->fetchAll();
         if($tasks) return $this->processTasks($tasks);
@@ -175,7 +169,8 @@ class taskModel extends model
             ->from(TABLE_TASK)->alias('t1')
             ->leftjoin(TABLE_PROJECT)->alias('t2')
             ->on('t1.project = t2.id')
-            ->where('t1.owner')->eq($account);
+            ->where('t1.owner')->eq($account)
+            ->andWhere('t1.deleted')->eq(0);
         if($status != 'all') $sql->andwhere('t1.status')->in($status);
         $stmt = $sql->query();
         while($task = $stmt->fetch())
@@ -188,22 +183,24 @@ class taskModel extends model
     /* 获得story对应的task id=>name列表。*/
     public function getStoryTaskPairs($storyID, $projectID = 0)
     {
-        $sql = $this->dao->select('id, name')
+         return $this->dao->select('id, name')
             ->from(TABLE_TASK)
-            ->where('story')->eq((int)$storyID);
-        if($projectID > 0) $sql->andwhere('project')->eq((int)$projectID);
-        return $sql->fetchPairs();
+            ->where('story')->eq((int)$storyID)
+            ->andWhere('deleted')->eq(0)
+            ->onCaseOf($projectID)->andWhere('project')->eq($projectID)->endCase()
+            ->fetchPairs();
     }
 
     /* 获得story对应的task数量。*/
     public function getStoryTaskCounts($stories, $projectID = 0)
     {
-        $sql = $this->dao->select('story, COUNT(*) AS tasks')
+        $taskCounts = $this->dao->select('story, COUNT(*) AS tasks')
             ->from(TABLE_TASK)
-            ->where('story')->in($stories);
-        if($projectID > 0) $sql->andwhere('project')->eq((int)$projectID);
-        $sql->groupBy('story');
-        $taskCounts = $sql->fetchPairs();
+            ->where('story')->in($stories)
+            ->andWhere('deleted')->eq(0)
+            ->onCaseOf($projectID)->andWhere('project')->eq($projectID)->endCase()
+            ->groupBy('story')
+            ->fetchPairs();
         foreach($stories as $storyID) if(!isset($taskCounts[$storyID])) $taskCounts[$storyID] = 0;
         return $taskCounts;
     }
diff --git a/trunk/module/task/view/view.html.php b/trunk/module/task/view/view.html.php
index fa6863a7ba..742930a9f5 100644
--- a/trunk/module/task/view/view.html.php
+++ b/trunk/module/task/view/view.html.php
@@ -26,7 +26,7 @@
 
 <div class='yui-d0'>
   <div id='titlebar'>
-    <div id='main'>TASK #<?php echo $task->id . $lang->colon . $task->name;?></div>
+    <div id='main' class='<?php if($task->deleted) echo 'deleted';?>'>TASK #<?php echo $task->id . $lang->colon . $task->name;?></div>
     <div>
     <?php
     $browseLink = $app->session->taskList != false ? $app->session->taskList : $this->createLink('project', 'browse', "projectID=$task->project");
@@ -34,8 +34,11 @@
     //if(!($task->status != 'closed' and $task->status != 'cancel' and common::printLink('task', 'close',      "taskID=$task->id", $lang->task->buttonClose)))      echo $lang->task->buttonClose . ' ';
     //if(!($task->status != 'closed' and $task->status != 'cancel' and common::printLink('task', 'cancel',     "taskID=$task->id", $lang->task->buttonCancel)))     echo $lang->task->buttonCancel . ' ';
     //if(!($task->status == 'closed' or $task->status == 'cancel'  and common::printLink('task', 'activate',   "taskID=$task->id", $lang->task->buttonActivate)))   echo $lang->task->buttonActivate . ' ';
-    if(!common::printLink('task', 'edit',  "taskID=$task->id", $lang->task->buttonEdit)) echo $lang->task->buttonEdit . ' ';
-    if(!common::printLink('task', 'delete',"projectID=$task->project&taskID=$task->id", $lang->task->buttonDelete, 'hiddenwin')) echo $lang->task->buttonDelete . ' ';
+    if(!$task->deleted)
+    {
+        if(!common::printLink('task', 'edit',  "taskID=$task->id", $lang->task->buttonEdit)) echo $lang->task->buttonEdit . ' ';
+        if(!common::printLink('task', 'delete',"projectID=$task->project&taskID=$task->id", $lang->task->buttonDelete, 'hiddenwin')) echo $lang->task->buttonDelete . ' ';
+    }
     echo html::a($browseLink,  $lang->goback);
     ?>
     </div>
@@ -60,8 +63,11 @@
         //if(!($task->status != 'closed' and $task->status != 'cancel' and common::printLink('task', 'close',      "taskID=$task->id", $lang->task->buttonClose)))      echo $lang->task->buttonClose . ' ';
         //if(!($task->status != 'closed' and $task->status != 'cancel' and common::printLink('task', 'cancel',     "taskID=$task->id", $lang->task->buttonCancel)))     echo $lang->task->buttonCancel . ' ';
         //if(!($task->status == 'closed' or $task->status == 'cancel'  and common::printLink('task', 'activate',   "taskID=$task->id", $lang->task->buttonActivate)))   echo $lang->task->buttonActivate . ' ';
-        if(!common::printLink('task', 'edit', "taskID=$task->id", $lang->task->buttonEdit)) echo $lang->task->buttonEdit . ' ';
-        if(!common::printLink('task', 'delete',"projectID=$task->project&taskID=$task->id", $lang->task->buttonDelete, 'hiddenwin')) echo $lang->task->buttonDelete . ' ';
+        if(!$task->deleted)
+        {
+            if(!common::printLink('task', 'edit', "taskID=$task->id", $lang->task->buttonEdit)) echo $lang->task->buttonEdit . ' ';
+            if(!common::printLink('task', 'delete',"projectID=$task->project&taskID=$task->id", $lang->task->buttonDelete, 'hiddenwin')) echo $lang->task->buttonDelete . ' ';
+        }
         echo html::a($browseLink,  $lang->goback);
         ?>
       </div>