Edit: My Code is for Thickbox version 3 or 3.1
Heres a slightly tweaked version. It has better cosmetics, and centers the image thumbnails.
PHP Code:
{if $images ne ""}
<div style="white-space:nowrap;color:#D90000;font-weight:bold;padding:2px;margin:10px 0 4px;">{$lng.lbl_detailed_images} ¬</div>
<table width="100%" ><tr>
{assign var=loop value=1}
{section name=image loop=$images}
<td class = image_bdr align="center">
{if $images[image].avail eq "Y"}
{if $images[image].tmbn_url}
<div style="white-space: nowrap;padding:0 0 1px 3px;"><a href="{$images[image].tmbn_url}" title=" {$images[image].alt|escape}" class="thickbox" rel="lightbox_detailed"><img src="{$images[image].tmbn_url}" width="100" style="border:0;" alt="{$lng.lbl_click_to_enlarge|escape}" /> </a></div>
{else}
<div style="white-space: nowrap;padding:0 0 1px 3px;"><a href="{$xcart_web_dir}/image.php?id={$images[image].imageid}&type=D" title=" {$images[image].alt|escape}" class="thickbox" rel="lightbox_detailed"><img src="{$SkinDir}/thickbox/files/zoom.gif" style="border:0;" alt="{$lng.lbl_click_to_enlarge|escape}" /> {$images[image].alt|escape}{if $images[image].alt|escape eq ""} {$lng.lbl_image} {math equation="value+1" value=$smarty.section.image.index}{/if}</a></div>
{/if}
{/if}
</td>
{* change the number below for how many images wide you want *}
{if $loop eq 5} </tr><tr> {assign var=loop value=0}
{/if}
{assign var=loop value=$loop+1}
{/section}</tr>
</table>
<script type="text/javascript" src="{$SkinDir}/thickbox/files/jquery-compressed.js"></script>
<script type="text/javascript" src="{$SkinDir}/thickbox/files/thickbox.js"></script>
<style type="text/css" media="all">@import "{$SkinDir}/thickbox/files/thickbox.css";</style>
{/if}
Also need to add this to your css file
Code:
.image_bdr {BORDER-RIGHT: 1px solid; BORDER-TOP: 1px solid; BORDER-LEFT: 1px solid; BORDER-BOTTOM: 1px solid}