Width of the GridView does not become to 0

Question

In my GridView I am trying Template fields to have width 0. I am using this code but still does not work. please help
' runat=server/>

             </ItemTemplate>

             </asp:TemplateField>
            <asp:TemplateField ItemStyle-Width="0px">
            <ItemTemplate>
            <asp:HiddenField ID="hdnSeqID" Value='<%#Bind("Seq_ID") %>' runat=server/>                 
            </ItemTemplate>           


            </asp:TemplateField>

            <asp:TemplateField ItemStyle-Width="0px">
            <ItemTemplate>
            <asp:HiddenField ID="hdnFormCode" Value='<%#Bind("Form_Code") %>' runat=server/>                 
            </ItemTemplate>           
                <ItemStyle Width="0px" />

            </asp:TemplateField>


        </Columns>
        <RowStyle BackColor="#EFF3FB" />
        <EditRowStyle BackColor="#2461BF" />
        <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
        <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
        <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
        <AlternatingRowStyle BackColor="White" />
    </asp:GridView>