Looks like you assume that you can use createHTMLDocument() to download and parse a HTML file from the URL you've passed as the first parameter. That is not the case, createHTMLDocument() always creates an empty document.
Also, the parameters you've passed to the function are those of createDocument(). createHTMLDocument() takes only one parameter, the document title. But even if you'd use createDocument(), the first parameter is the URI of the namespace, not the source document.
Unfortunately there's no way to download and manipulate external web site's HTML using JavaScript alone. The closest you can get is displaying the document in an iframe.