As suggested here (I think it was Eric), I did away with the embedded javascript in my web page and used a variant of the iframe code. Turns out that my remaining issue (the form seeming to be "modal" when the page hosting it was displayed) was due to my very basic mistake when I specified the iframe: I forgot the closing </iframe> tag. Net result was that, when display, the browser treated all the rest of the page as part of the iframe (or something like that) since it wasn't explicitly closed.

You can see the latest version of this (remember - still POC / in progress!) at: http://stronggroup.com/testhlv -- form is on the "Analysis" page. Making progress...!