This way
<div style="background-image:url('download.jpg');">
<div style="min-width:; width: 960px; height: 40px;
margin: 0px auto;">
<div style="padding-left: 10px; padding-top:5px;">
<table>
<tr>
<td>
<a href="Enter.aspx" id="aEnterData">Enter Data</a>
</td>
<td>
<a href="Veiw.aspx" id="aVeiwData">Veiw Data</a>
</td>
</tr>
</table>
</div>
</div>
<asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
</asp:contentplaceholder>
</div>
i added this it works