you can use absolute position of div, that will rotate according to the screen :
<div id="dvUpdateProgress" style="left: 44%; float: none;
top: 27%; z-index: 1; position: fixed;">
<table class="noborder">
<tr>
<td align="center">
Please Wait...
</td>
</tr>
<tr>
<td>
<img src="../Images/loadingsmall.gif" alt="X" title="Please Wait" />
</td>
</tr>
</table>
</div>
for more in detail follow this :
How To Make Floating and Dimming a Div using JavaScript[
^]
Hope this will help you.
Dont forget to mark as answer if it helps. :)