Problem
I’m using the Apprise jQuery plugin to show a fancy alert box on a webpage. The problem is I also have the embedded iFrame code from YouTube on the page. When the fancy alert box shows in Internet Explorer, it shows behind the video. It works in all other browsers.
Solution
The solution is to add the wmode=transparent or wmode=opaque parameter to the youtube url. Have the iframe point to something like the following:
https://youtube.com/watch?v=xyz%3Fwmode%3Dtransparent
Source: http://stackoverflow.com/questions/5281002/z-index-and-iframes