default value in form action filed

in the old editor i manage to get a default value in the form tag action
<input style="width: 100%" type="hidden" id="txtAction" value="/sendform/3"/> in the fck_form-html
but I can't figure out how to do it in the new one. I've tried
id : 'action',
type : 'text',
label : editor.lang.form.action,
'default' : '/sendform/3',
accessKey : 'T'
in the form.js file but nothing happens.I've even tried to destroy the file by inserting äåöäöå to se in anything would happen but absolutly nothing.
I've use php to insert the editor
$CKEditor = new CKEditor();
$CKEditor->basePath = '/admin/ckeditor/';
$CKEditor->config['toolbar'] = "lada";
$CKEditor->editor("sida", "$sida");