I have a table in ASP.Net like this.

```
 <table width="100%">
 <tr>
     <td rowspan="4" colspan="2" class="style1">
     </td>                                        
     <td>
         <asp:Label ID="label1" runat="server" Text="Label1"></asp:Label>
     </td>
     <td>
         <asp:TextBox ID="TextBox4" runat="server" Width="136px">
         </asp:TextBox>
     </td>
 </tr>
 <tr>        
    <td><asp:Label ID="label2" runat="server" Text="Label2"></asp:Label></td>
    <td><asp:TextBox ID="TextBox1" runat="server" Width="136px">
         </asp:TextBox></td>
 </tr>
 <tr>        
    <td><asp:Label ID="label3" runat="server" Text="Label3"></asp:Label></td>
    <td><asp:TextBox ID="TextBox2" runat="server" Width="136px">
         </asp:TextBox></td>
 </tr>
 <tr>        
    <td><asp:Label ID="label4" runat="server" Text="Label4"></asp:Label></td>
    <td><asp:TextBox ID="TextBox3" runat="server" Width="136px">
         </asp:TextBox></td>
 </tr>
 </table> 

```

I want to give border line to first td element which contains the colspan and rowspan. Not to the entire row.
Please give solution.