用javascript隐藏Detailsview字段

<script type="text/javascript">
    function HideShowPromo(chk) {
        if (chk.checked == true) 
            //.style.display = 'block';
        else 
            //.style.display = 'none';
    }
</script>

<asp:DetailsView ID="DetailsView1" runat="server" AutoGenerateRows="false">
    <Fields>
        <asp:TemplateField HeaderText="Use Promotional Code:">
            <InsertItemTemplate>
                <asp:CheckBox ID="cbUsePromo" runat="server" />
            </InsertItemTemplate>
            <EditItemTemplate>
                <asp:CheckBox ID="cbUsePromo" runat="server" Checked='<%# Bind("_usePromo") %>' />
            </EditItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Promotional Code:">
            <InsertItemTemplate>
                <asp:TextBox ID="txtPromoCode" runat="server" MaxLength="10"></asp:TextBox>
            </InsertItemTemplate>
            <EditItemTemplate>
                <asp:TextBox ID="txtPromoCode" runat="server" Text='<%# Bind("_promo") %>' MaxLength="10"></asp:TextBox>
            </EditItemTemplate>
        </asp:TemplateField>
    </Fields>
</asp:DetailsView>      

以及背后的密码:

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        DetailsView1.DefaultMode = DetailsViewMode.Insert;              
        ((CheckBox)DetailsView1.FindControl("cbUsePromo")).Attributes.Add("onclick", "HideShowPromo(this)");
    }
}

我可以选择“txtPromoCode”文本框并将其隐藏,但它会留下headertext。我想把整个场地都藏起来。