I have this code defined in a Web form:

<tr id="ShopDisplay" visible=true> 
<td class="Label"><%=LXFramework.GetMes("Message", "Shop")%>:</td>
<td><asp:textbox ID="Shop" runat="server" Columns="60" style="Width: 500px;" CssClass=InputReadOnly Enabled=false></asp:textbox>
</tr>

If I try to do:

            toPage.ShopDisplay.Visible = False

I obtain:

Object variable or With block variable not set.

Why aren't we allowed to change the Visible property?