you can remove the delete button from the admin/contents_detail.php page.
or you could comment it out:
<!--<a href="contents_delete.php?ContentID=<?php echo(rawurlencode($row_WADAContents['ContentID'])); ?>" title="Delete" class="shiftright">
<img src="../images/btn_delete.png" border="0" name="Delete" alt="Delete" /></a>-->