Change control postion dynamically in ASP.NET

I control visibility of buttons on a web page according to the type of a user.Visibility is determined in the Page_Load event. But there's one problem with the position of the controls.Appearance is awful.How can I make so that one button's开发者_Python百科 top is the same as another button's top?

The markup is as follows: (added by OP in comment)

 <tr> 
     <td style="width: 200px; height: 20px;">
             <asp:Button ID="btnStajStatic" runat="server" 
                  OnClick="btnStajStatic_Click" Text="Staj statistika" 
                  Width="120px" BackColor="WhiteSmoke" BorderStyle="Solid" />
     </td>
 </tr>