protected void RemovePageDataSource_Click(object sender, ImageClickEventArgs e)
    {
        Hashtable State = (Hashtable)HttpRuntime.Cache[Session.SessionID];
        Util util = new Util();
        if (util.CheckSessionTimeout(State, Response, "../Default.aspx")) return;

        string selected_raw_text = PageDataSources.SelectedValue;
        int index = Convert.ToInt32(selected_raw_text.Substring( 1,selected_raw_text.IndexOf(")")-1));
        DataSources DS = new DataSources();
        DS.RemovePageDataSource(State, index - 1);

        if (PageDataSources.Items.Count == 1)
        {
             RemovePageDataSource.Style.Value = "display:none";
             ManageDataPanel.Style.Value = ManageDataPanel.Style.Value.Replace("block", "none");
             PageDataSources.Items.Clear();
             EventField.Items.Clear();
             return;
        }
        else
         LoadData();
    }