public void updateUI()
    {
        initServerButtons(ServerManagerment.Instance.lastServer);


        for (int i = 0; i < ScrollContent.transform.childCount; i++)
        {
            GameObject go = ScrollContent.transform.GetChild(i).gameObject;
            DestroyImmediate(go);
        }

        List <Json_ServerInfo> serverList = ServerManagerment.Instance.getAllServer();

        foreach (Json_ServerInfo each in serverList)
        {
            GameObject   obj    = NGUITools.AddChild(ScrollContent.gameObject, serverButtonPrefab);
            ServerButton button = obj.GetComponent <ServerButton> ();
            button.initButton(each);
            button.fatherWindow = this;
            obj.AddComponent <UIDragScrollView> ();
        }
        UIGrid grid = ScrollContent.GetComponent <UIGrid> ();

        grid.enabled = true;
        grid.Reposition();
        if (GuideManager.Instance.guideUI != null)
        {
            GuideManager.Instance.hideGuideUI();
        }
        if (serverList.Count > 8)
        {
            downArrow.SetActive(true);
        }
    }
    /* methods */
    protected override void DoEnable()
    {
        base.DoEnable();

        UiManager.Instance.backGround.switchBackGround("loginBackGround");
        initServerButtons(ServerManagerment.Instance.lastServer);
        List <Json_ServerInfo> serverList = ServerManagerment.Instance.getAllServer();

        foreach (Json_ServerInfo each in serverList)
        {
            GameObject   obj    = NGUITools.AddChild(ScrollContent.gameObject, serverButtonPrefab);
            ServerButton button = obj.GetComponent <ServerButton> ();
            button.initButton(each);
            button.fatherWindow = this;
            obj.AddComponent <UIDragScrollView> ();
        }
        UIGrid grid = ScrollContent.GetComponent <UIGrid> ();

        grid.enabled = true;
        grid.Reposition();
        if (GuideManager.Instance.guideUI != null)
        {
            GuideManager.Instance.hideGuideUI();
        }
        if (serverList.Count > 8)
        {
            downArrow.SetActive(true);
        }
        MaskWindow.UnlockUI();
    }