private void comboBox3_SelectedIndexChanged(object sender, EventArgs e)
 {
     if (comboBox3.SelectedIndex < 0)
     {
         MessageBox.Show("Select Category!!!!");
     }
     else
     {
         string       catName  = comboBox3.SelectedItem.ToString();
         CategorySer  catS     = new CategorySer();
         int          catID    = catS.GetCategoryID(catName, LogIn.user_ID);
         ShareTaskSer tS       = new ShareTaskSer();
         List <int>   tkIDList = tS.GetAllTasksFromShareTasks(catID);
         TaskSer      taskService;
         string       tittle;
         for (int i = 0; i < tkIDList.Count; i++)
         {
             taskService = new TaskSer();
             tittle      = taskService.GetTaskTittle(catID, tkIDList[i]);
             cBCategory.Items.Add(tittle);
         }
     }
 }