Need Centering

How would I center this code:

I tried the <center></center> but it doesn't work.

$results .= "<div id='eb_item'>
<div class='item_title'><a id= 'out' href=\"http://rover.ebay.com/rover/1/711-53200-19255-0/1?campid=$ebay_id&toolid=10013&mpre=" . $item->ViewItemURLForNaturalSearch . "\" target='_blank' rel='nofollow'>" . $item->Title . "  </a></div>";
$results .= "<div class='item_image'><a id= 'out' href=\"http://rover.ebay.com/rover/1/711-53200-19255-0/1?campid=$ebay_id&toolid=10013&mpre=" . $item->ViewItemURLForNaturalSearch . "\" target='_blank' rel='nofollow'><img src=\"$item->GalleryURL\" alt=\"$item->Title \" width=100 height=95></a></div> \n";
$results .= "<div class='currprice'>"  ;
$results .= "<span id='wbar'><b>Price:</b></span> <span id='pricebar'> $" . $ConvertedCurrentPrice. "</span></div>\n";
$results .= "<div class='ends'></div><br><div>
<a id= 'out' href=\"http://rover.ebay.com/rover/1/711-53200-19255-0/1?campid=$ebay_id&toolid=10013&mpre=" . $item->ViewItemURLForNaturalSearch . "\" target='_blank' rel='nofollow'><img src='../images/details.gif' border=0 alt=''></a></div><br>\n";
$results .= "</div>\n";

PHP:

 

This isn't really a PHP question, but:

style="width: xxx; margin: auto;"

Code (markup):

 

In the CSS find

and put

margin: 0 auto;

Code (markup):

 

Thanks a lot.