Problem with passing values

Heres my code:
include("fckeditor/fckeditor.php");
$oFCKeditor = new FCKeditor('fck_contents') ;
$oFCKeditor->BasePath = './fckeditor/' ;
$oFCKeditor->Height = '500';
$oFCKeditor->Value = '1' . $edit[0]['post_content'];
$oFCKeditor->Create();

when i click my update button it only passes '1' even i already edit the contents inside the fck..

heres my update button:
<input type="button" value="Update" onClick="menuNav('catContentControlPanel.php','sample','editit='+tit.value+'&eid='+eid.value+'&editor='+fck_contents.value)">

just a simple fck_contents.value, i used this because the editor is inside ajax

any ideas?