title: Fatal error: Using $this when not in object context with pdo wrapper class
body: <p>I am using <a href="http://blog.csdn.net/btbdylq/article/details/6826225" rel="nofollow">simpleSQL - PDO</a> class in my php application,<br>
  and using by this code:  </p>
  
  <pre><code>$where['username']=$_POST['username'];
  $where['password']=md5($_POST['password']);
  
  $DB = new DB();
  $res=$DB-&gt;buildQuery('tbl_admin',$where);
  </code></pre>
  
  <p>it is working fine in localhost, but in online server it get the error this:  </p>
  
  <pre><code>Fatal error: Using $this when not in object context in DB.php on line 230  
  </code></pre>
  
  <p>line no. 230 in DB class is:  </p>
  
  <pre><code>$ item  = $ this- &gt; instance- &gt; quote ($ this- &gt; escape ($ item)); 
  </code></pre>
  
  <p>Where is my problem?</p>