iframe

This question is somewhat related to this forum. Otherwise, please let me know a good iframe forum:

I saw a web design like this:

With the same document there are three sections:

1) main body z-index =0

2) iframe z-index = 100 opacity=50%

3) div popup z-index = 500

It behaves like this:

You got the div like a popup (on top), the iframe 50% opacity to allow looking through to see the main body text.

In this case, is the iframe necessary? And is the iframe employed reasonably for this case?

Thanks

Scott

Also in #CSS _↴