Intergration fckeditor with AJAX

<script>
function getXMLHttpRequestObject()
{
    if(window.XMLHttpRequest) return new window.XMLHttpRequest();
    else if(window.ActiveXObject) return new window.ActiveXObject("Msxml2.XMLHTTP"); 
    else return new window.ActiveXObject("Microsoft.XMLHTTP");
    return 0;
}

function post(form,url,target)
{
var formdata = "";
xmlhttp = getXMLHttpRequestObject();
for (i=0; i < thisform.length; i++)
    {
   if(thisform.elements[i].type == "text")
      { //Handle Textbox's
      formdata = formdata + thisform.elements[i].name + "=" + escape(thisform.elements[i].value) + "&";
      }
   else if(thisform.elements[i].type == "textarea")
      { //Handle textareas
      formdata = formdata + thisform.elements[i].name + "=" + escape(thisform.elements[i].value) + "&";
      }
   else if(thisform.elements[i].type == "checkbox")
      { //Handle checkbox's
      formdata = formdata + thisform.elements[i].name + "=" + thisform.elements[i].checked + "&";
      }
   else if(thisform.elements[i].type == "radio")
   { //Handle Radio buttons
   if(thisform.elements[i].checked==true)
      {
      formdata = formdata + thisform.elements[i].name + "=" + thisform.elements[i].value + "&";
      }
   }
   else
      {
      formdata = formdata + thisform.elements[i].name + "=" + escape(thisform.elements[i].value) + "&";
      }
    }
xmlhttp.onreadystatechange = function()
   {
   var wait = document.getElementById(target);
   wait.innerHTML = '<div id=\"ajax_loader\"><table border=\"0\"><tr><td><img src=\"img_iconies/ajax_loader_search.gif\"> </td><td> Processing... please wait.</td></tr></table><div>';
   if ((xmlhttp.readyState == 4) && (xmlhttp.status == 200)) 
      {
      var request_response = document.getElementById(target);
      request_response.innerHTML = xmlhttp.responseText;
      }
    }
xmlhttp.open("POST", url);
xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlhttp.send(formdata);
return false;
}

</script>
<script type="text/javascript" src="js/fckeditor/fckeditor.js"></script>
<?php include("conn_mysql.inc.php");?>
<?php include("fckeditor.php") ;?>
<?php
$sql_newsletter = "
SELECT *
FROM root_newsletters
ORDER BY nwl_created DESC";       
$result_newsletter = mysql_query($sql_newsletter);
$numRows_newsletter = mysql_num_rows($result_newsletter);
$row_newsletter = mysql_fetch_assoc($result_newsletter);
?>
<form action="" onsubmit="post(this,'post.php','frame');return false;" method="post" enctype="multipart/form-data">
<?php

$val = $row_newsletter['nwl_content'];
$sBasePath = $_SERVER['PHP_SELF'] ;
$sBasePath = substr( $sBasePath, 0, strpos( $sBasePath, "_samples" ) ) ;
$oFCKeditor = new FCKeditor('content') ;
$oFCKeditor->BasePath   = 'js/fckeditor/' ;
$oFCKeditor->Value      = "$val" ;
$oFCKeditor->Create() ;
?>
<input type="submit" name="submit" value="Submit" />
</form>