Topic: Embed Simple Viewer in HTML for multiple galleries

I am redesigning a web page that used to include Simple Viewer. Because of the huge ammount of galleries I am still going to be using it. The old page used frames and the lay out of the new one is going to be done with CSS.
Now, here is the problem: I can't embed the movie into the HTML page. It works fine when I include it in an iframe but that is not the idea.
First of all, I have the multiple galleries folders, EACH containing all the documents from Simple Viewer (Images and thums folders, index.html, XML, swfobject.js and viewer.swf). In my HTML page I have created a div called "flashcontent" that is where the movie .swf should be loaded and I also have a menu item for each gallery with links to their index.html (all with the proper route).
And here is the problem: when I click in one of the links, the gallery opens in a new window, not embeded in the HTML. What it does (and it makes sense) is to open an HTML page, not a SWF movie.
These are the instructions given in the Airtight webpage but, not only it doesn't work but I understand why! Obviously I am missing something here and I would appreciate a bit of light on the matter.
Thanks in advance.