I have a certain snippet of content that I would only like to be displayed when a user clicks a certain link.

After clicking, a "floating window" would then appear in the center of the current browser, above the rest of the page. This window should be able to contain HTML code.

I've seen similar things where the container follows the mouse, but I really don't need that...

I was supposing you'd put the content in a DIV tag, then made it visible on click, but in recent experiments, it displaces the underlying layout.

Do I need absolute positioning? Do I need to mess with the z-index?

Any help would be appreciated.