Request-URI Too Large The requested URL ' s length exceeds the capacity limit for this server

wenn ich mit tinymce bekomme ich

Request-URI Too Large The requested URL ' s length exceeds the capacity limit for this server.

mein code:-

  <!-- TinyMCE -->
<script type="text/javascript" src="../jscripts/tiny_mce/tiny_mce.js"></script>
<script type="text/javascript">
    tinyMCE.init({
        //mode : "textareas",
        mode : "specific_textareas",
        editor_selector : "myBasicEditor",
        theme : "simple"
    });
</script>
<!-- /TinyMCE -->



        if(tinyMCE.get('txtourcmnt').getContent() !="" )
        {
                //var test = tinyMCE.get('txtourcmnt').getContent();
                //alert(test);
                var ordid = '<?php echo $ordid; ?>';
                var cmnt  = tinyMCE.get('txtourcmnt').getContent();
                cmnt = encodeURIComponent(cmnt);
                var typ   = 'o';
        }
        if(cmnt != "")
        {
            var url = "display_comments.php?ordid="+ordid+"&cmnt="+cmnt+"&typ="+typ;        
            xmlHttp = GetXmlHttpObject(funcsubcatval);
            xmlHttp.open("POST", url , true);
            alert(url);
            xmlHttp.send(null);
        }