public static function newInstance()
 {
     if (!self::$instance instanceof self) {
         self::$instance = new self();
     }
     return self::$instance;
 }
function seo_delete_item($item_id)
{
    ModelSeo::newInstance()->deleteItem($item_id);
}
<?php

$detail = ModelSeo::newInstance()->getAttrByItemId($item_id);
?>

<style>
  .add_item .s-minus {background: url('<?php 
echo osc_base_url();
?>
oc-content/plugins/all_in_one/css/icons.png') no-repeat;background-position:-432px -95px;width: 15px;height: 14px;float: left;margin-left: 0px;margin-top: 0px;margin-right: 5px;margin-bottom:0px}
  .add_item .s-plus {background: url('<?php 
echo osc_base_url();
?>
oc-content/plugins/all_in_one/css/icons.png') no-repeat;background-position:-407px -95px;width: 15px;height: 14px;float: left;margin-left: 0px;margin-top: 0px;margin-right: 5px;margin-bottom:0px}
  .seo_info {padding: 6px 0 0 0;color:#aaa;font-style:italic;}

  #show_hide_seo {cursor:pointer;}
  #seo_table, #seo_table table, #seo_table table tr {width:100%;float:left;clear:both;}
  #seo_table table tr {margin:3px 0;}
  #seo_table td.lab {max-width:25%;width:auto;float:left;min-width:100px}
  #seo_table td.inp {width:40%;float:left;margin:0 2%}
  #seo_table td.des {width:34%;float:left;margin-left:1%;font-size:12px;}
  #seo_table input {width:100%;max-width:100%;float:left;padding: 6px 5px}
  #seo_table label {width:100%;max-width:100%;float:left;padding: 3px 0 0 0;margin:0;}
</style>

<div style="clear:both"></div>
<div class="box"></div>
<h2 id="show_hide_seo"><div id="ic" class="s-plus"></div><span><?php 
_e('Meta Options (advanced)', 'all_in_one');
?>