Csharp:asp.net CheckBoxList databind

<style type="text/css">
 
 
.geovindu INPUT
{
 color:black;
 border-style: none;
 font-family: Tahoma;
 font-size: 7px;
 margin-right: 5px
}

.geovindu td 
{
     /*  font-size:x-large;*/
    width:300px;
   
}

    </style>

<asp:CheckBoxList ID="CheckBoxList1" runat="server" RepeatDirection="Horizontal" AppendDataBoundItems="True" DataTextField="B_Name" DataValueField="B_EnglishName" RepeatColumns="6" CellPadding="5"
           CellSpacing="5" RepeatLayout="Table" BorderStyle="Outset" CssClass="geovindu">
        </asp:CheckBoxList><br />
        <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="確定" /></div>

/// <summary>
        /// CheckBoxList數據源
        /// 塗聚文
        /// 20130705
        /// 
        /// </summary>
        private void setCheckBoxList()
        {
           DataTable dt = new DataTable();
           CheckBoxList1.Items.Clear();
          dt = geovindu_branchBLL.SelectGeovindu_branchNameDt();
          CheckBoxList1.DataSource = dt;
          this.CheckBoxList1.DataTextField = "B_Name";
          this.CheckBoxList1.DataValueField = "B_EnglishName";
          CheckBoxList1.DataBind();

        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                setCheckBoxList();
            }

      
        }
        /// <summary>
        /// 獲取選擇的項目
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void Button1_Click(object sender, EventArgs e)
        {
            string variable = string.Empty;
            int i = 0;
            foreach (System.Web.UI.WebControls.ListItem oItem in CheckBoxList1.Items)
            {
                if (oItem.Selected) // if you want only selected
                {
                    if (i ==0)
                    {
                       variable = oItem.Value; 
                    }
                    else
                    {
                        variable = variable + "," + oItem.Value;
                    }
                    i++;
                }
                // otherwise get for all items
                //variable = oItem.Value;
                
            }

            //傳值給父頁面 
            this.Page.Controls.Add(new LiteralControl(string.Format("<script>opener.document.form1.txtShoppingDealsBranch.value='{0}'</script>", variable))); 
	 
	         //關閉此視窗 
	        this.Page.Controls.Add(new LiteralControl("<script>window.close();</script>"));