ASP.NET - datalist contol gridline

i use datalist control to show the items name

<div style="float: left; padding-top: 10px; height: 400px; width: 318px;">
<asp:DataList ID="dtlspprodindex" runat="server" CellPadding="1" CellSpacing="1"
Height="375px" RepeatColumns="3" ItemStyle-Width="182px" ItemStyle-HorizontalAlign="Left"
BorderWidth="0px" Font-Bold="False" Font-Italic="False" Font-Names="Verdana"
BorderColor="#D2D3D5" Font-Overline="False" Font-Strikeout="False" Font-Underline="False"
GridLines="Vertical">
<ItemTemplate>
&nbsp;
<asp:HyperLink ID="hlinkpprodindex" runat="server" Text='<%# Databinder.Eval(Container.Dataitem,"Product").Trim() %>'
NavigateUrl=''
CssClass="categorytxt" Font-Bold="false" Style="text-transform: capitalize"></asp:HyperLink>
</ItemTemplate>

</asp:DataList></div>


i want a dashed line afeter first column and second column

i used gridline but that displays as solid line and i want dashed line so please provide sample code so i can slove it


thanks and regards