How to place an image over another?

Question

How to put an image over another bigger image, like on youtube, a play button is displayed on top of video thumbnail?

Answer 1

Make a semi-transparent PNG graphic with a "Play" symbol and the size you want (e.g. 240x320).

Let's say you named it "overlay.png", and let's say the YouTube-generated thumbnail is at http://img.ytimg.com/abcdefg/0.jpg

Now all you need in your code is this:

As long as your target audience is not still using IE6, you should be safe.