title: weird error with jquery sortable : is not a function
body: <p>I am getting a weird error when i am using jqueryui sortable. 
  It says,</p>
  
  <pre><code>$(this).sortable(); is not a function.
  </code></pre>
  
  <p>How to solve this?</p>
  
  <p><strong>edit</strong>
  heres my header code:</p>
  
  <pre><code>&lt;script src="jquery.min.js"&gt;&lt;/script&gt;
  &lt;script src="jquery.ui.core.js"&gt;&lt;/script&gt;
  &lt;script src="jquery.ui.widget.js"&gt;&lt;/script&gt;
  &lt;script src="jquery.ui.mouse.js"&gt;&lt;/script&gt;
  &lt;script src="jquery.ui.sortable.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>and heres the code i am using to refresh my edit my xml file.</p>
  
  <pre><code>$("#sortable").sortable(
  {
      update : function(event, ui) {
          //var change = $(this).sortable('toArray').toString();
          // $('#show').html(change); 
          var order = $(this).sortable('toArray');
          //var order = $(this).val;
      $("#show").load("update_engine_xml.jsp?order="+ order);
          //$("#showid").html(ui.item.context.id+" "+event.target.id);                                            
      }
  });
  </code></pre>
  
  <p>EDIT: 2 
  any suggestions why i am getting this error?!</p>