arkadaşlar hatayı buldum en sonunda, tek bir kod yazmakla olay bitecek.

birisi bu konuda yardımcı olursa çok az bir kod satırıyla olay burada sonlanacak.
icerikekle.php dosyası içerisindeki tüm kodları olduğu gibi aşağıya yapıştırıyorum..
ben muhtemelen, TinyMCE editörün yazı metninin girildiği alanı (açıklama) post edemiyorum ya da ona benzer bir durum söz konusu...
bir kez daha inceleyip ufak bir yardımda daha bulunursanız çok memnun olurum.
<?
include "header.php";
$kat_id=$_GET['kat_id'];
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-9" />
<title>Yönetim Paneli - İçerik Ekle</title>
<script language="javascript" type="text/javascript" src="editor/jscripts/tiny_mce/tiny_mce.js"></script>
<script language="javascript" type="text/javascript">
tinyMCE.init({
// General options
mode : "textareas",
theme : "advanced",
plugins : "safari,pagebreak,style,layer,table,save,advhr,advimage,advlink,emotions,iespell,inlinepopups,insertdatetime,preview,media,searchreplace,print,contextmenu,paste,directionality,fullscreen,noneditable,visualchars,nonbreaking,xhtmlxtras,template",
// Theme options
theme_advanced_buttons1 : "save,newdocument,|,bold,italic,underline,strikethrough,|,justifyleft,justifycenter,justifyright,justifyfull,|,styleselect,formatselect,fontselect,fontsizeselect",
theme_advanced_buttons2 : "cut,copy,paste,pastetext,pasteword,|,search,replace,|,bullist,numlist,|,outdent,indent,blockquote,|,undo,redo,|,link,unlink,anchor,image,cleanup,help,code,|,insertdate,inserttime,preview,|,forecolor,backcolor",
theme_advanced_buttons3 : "tablecontrols,|,hr,removeformat,visualaid,|,sub,sup,|,charmap,emotions,iespell,media,advhr,|,print,|,ltr,rtl,|,fullscreen",
theme_advanced_buttons4 : "insertlayer,moveforward,movebackward,absolute,|,styleprops,|,cite,abbr,acronym,del,ins,attribs,|,visualchars,nonbreaking,template,pagebreak",
theme_advanced_toolbar_location : "top",
theme_advanced_toolbar_align : "left",
theme_advanced_statusbar_location : "bottom",
theme_advanced_resizing : true,
// Example content CSS (should be your site CSS)
content_css : "css/content.css",
// Drop lists for link/image/media/template dialogs
template_external_list_url : "lists/template_list.js",
external_link_list_url : "lists/link_list.js",
external_image_list_url : "lists/image_list.js",
media_external_list_url : "lists/media_list.js",
// Replace values for the template plugin
template_replace_values : {
username : "Some User",
staffid : "991234"
}
});
</script>
<style type="text/css">
body {
margin-left: 0px;
margin-top: 0px;
margin-right: 0px;
margin-bottom: 0px;
}
</style>
<link href="style.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div style="background:url(images/bg.jpg); "><img src="images/p1.png" width="261" height="44" /></div>
<table width="100%" height="610" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="17%" align="center" valign="top" bgcolor="#EEEEEE">
<? include("menu.php"); ?>
</td>
<form action="" method="post" enctype="multipart/form-data" name="form1" id="form1">
<td width="83%" align="center" valign="top">
<table width="100%" height="34" border="0" cellpadding="0" cellspacing="2">
<tr>
<td width="22%" height="34" align="left" bgcolor="#EEEEEE" class="koyuyazi">İçerik Ekleme</td>
<td width="18%" align="center" bgcolor="#3399CC" class="koyuyazi">
<input name="kaydet" type="submit" class="submit" id="kaydet" value="Kaydet" /></td>
<?
if (!empty($kat_id))
{
?>
<td width="18%" align="center" bgcolor="#3399CC" class="koyuyazi"><a href="icerikler.php?id=<?=$kat_id ?>" class="menu">Listeyi Görüntüle </a></td>
<?
}
?>
<td width="42%" align="left" bgcolor="#EEEEEE" class="koyuyazi"><div style="height:25px; line-height:normal" align="center" class="mesaj" id="mesaj"></div></td>
</tr>
</table>
<table width="100%" border="0" cellspacing="2" cellpadding="0">
<tr>
<td width="14%" align="left" valign="middle" bgcolor="#CDE6ED" class="acikyazi">Kategori </td>
<td width="86%" align="left" valign="middle" bgcolor="#CDE6ED" class="acikyazi">
<select name="katsec" id="katsec">
<?
if (empty($kat_id))
{
$sorgu = "SELECT * FROM kategoriler" ;
} else
{$sorgu = "SELECT * FROM kategoriler where id='$kat_id'" ; }
$sorgu = mysql_query($sorgu);
while($row=mysql_fetch_object($sorgu))
{
$id=$row->id;
$kat_adi=$row->kat_adi;
//$kat="$id-$kat_adi";
echo "<option value='".$id."'>$kat_adi</option>";
}
?>
</select></td>
</tr>
<?php
$kat_id=$_POST['katsec'];
$adi=$_POST['adi'];
$aciklama=$_POST['aciklama'];
if((isset($_POST['katsec'])) && ($_POST['katsec'] != "")) {
header("Location: icerikekle.php?kat_id=$kat_id"); {
echo "<script type='text/javascript'>goster('Kayıt Başarılı');</script>" ;
}
}
?>
<tr>
<td width="14%" align="left" valign="middle" bgcolor="#eeeeee" class="acikyazi">İçerik Adı </td>
<td align="left" valign="top" bgcolor="#eeeeee" class="acikyazi"><input name="adi" type="text" id="adi" size="30" /></td>
</tr>
<tr>
<td width="14%" align="left" valign="middle" bgcolor="#CDE6ED" class="acikyazi">İçerik Açıklama </td>
<td align="left" valign="top" bgcolor="#CDE6ED" class="acikyazi">
</td>
</tr>
</table>
<TEXTAREA NAME="textarea" ROWS="20" COLS="100"></TEXTAREA>
</form>
</td>
</tr>
</table>
</body>
</html>