Ajax double click editing + Post

http://nightly.ckeditor.com/4303/_samples/divreplace.html

<head>
   <script type="text/javascript" src="ckeditor/ckeditor.js"></script>

   <style id="styles" type="text/css">

      div.editable
      {
         padding-left: 15px;
         padding-right: 15px;
      }

      div.editable:hover
      {
         border-color: black;
      }

   </style>
   <script id="headscript" type="text/javascript">
   //<![CDATA[

// Uncomment the following code to test the "Timeout Loading Method".
// CKEDITOR.loadFullCoreTimeout = 5;
var editor;

window.onload = function()
{
   // Listen to the double click event.
   if ( window.addEventListener )
      document.body.addEventListener( 'dblclick', onDoubleClick, false );
   else if ( window.attachEvent )
      document.body.attachEvent( 'ondblclick', onDoubleClick );

};



function onDoubleClick( ev )
{
   // Get the element which fired the event. This is not necessarily the
   // element to which the event has been attached.
   var element = ev.target || ev.srcElement;

   // Find out the div that holds this element.
   element = element.parentNode;

   if ( element.nodeName.toLowerCase() == 'div'
       && ( element.className.indexOf( 'editable' ) != -1 ) )
      replaceDiv( element );
}


function replaceDiv( div )
{
   if ( editor )
      editor.destroy();

   editor = CKEDITOR.replace( div );
}

   //]]>
   </script>
</head>
<body>
<?php 
echo($_POST['editable']);


?>
<form method="post">
      <div class="editable">
        <p>
        testing

        </p>
      </div>
        <input type="submit" />
</form>
</body>
</html>