Revealing Editor functionality when using PHP Class

The only way that I have found that will reliably load an instance of CKEditor in a jQuery Dialog, when the content of the Dialog is loaded by an Ajax load from a PHP Script, is to use the PHP Class within the PHP SubScript.

I now have a different problem .... I can retrieve the content of the Editor:

var tex = CKEDITOR.instances.rte.getData();

But any attempt to get this instance for another purpose, such as Counting the Characters and Words, fails. Thus the following line returns an error "CKEDITOR undefined":

var editor = CKEDITOR.instances.rte;

Is this a fundamental problem? A feature/bug or am I missing something? I would be grateful for any assistance.