This may help you
<div id="div1" width="100%">
<table width="30%" align="left" border="1px">
<tr><td colspan="3">
<asp:Button ID="Button1" runat="server" Text="Button" />
</td>
</tr>
</table>
<table width="80%" align="right" border="1px">
<tr><td>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</td><td>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
</td>
<td>
<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>
</td></tr>
</table>
</div>