I thought I had this problem solved but it turns out, 'only in IE'. I have drop down menu items the client wants to have positioned over a Flash swf file that fades pictures into a banner. The basic problem is getting the div for the flash to respond to z-indexing, i.e. to have banner "sit behind" the drop down menu items.
Here are my list of things I've tried:
1. make sure all the elements involved have been 'positioned' either absolute or relative
2 make sure the flash div has a negative value and other elements positive values for their z-index values
3 make sure the param for the flash object is set to "opaque" and mode of "wmode"
This will work without the <embed> tag and the FF problems. It will also validate as HTML code.
An even better method is to use swfobject to detect and display Flash. This is great for SEO because it allows you to place alternate, regualar HTML content on the page to describe your Flash content. http://code.google.com/p/swfobject/
As for wmode, here's a detailed description from an old post:
Window Mode (wmode) - What's It For?
There are three window modes.
In windowless modes (like opaque), Flash Player doesn't have a hWnd. This means that the browser tells the Flash Player when and where to draw onto the browser's own rendering surface. The Flash movie is no longer being rendered on a higher level if you will. It's right there in the page with the rest of the page elements. The Flash buffer is simply drawn into whatever rectangle the browser says, with any Flash stage space not occupied by objects receiving the movie's background color.