在CSS的悬停覆盖图像

我需要一个div与图片bg来覆盖图像（有一些数量的透明度）时悬停。我需要能够有一个透明的覆盖，可以在任何图像的整个网站使用和重复使用。我的第一次尝试是圆的 - 至少说。因为我发现你不能翻转一个不可见的div，我设计了一个sandwhich系统，其中原始图像是第一层，覆盖是第二层，原始图像再次是第三层。这样，当您翻转时，原始图片会消失，并在原始图片上显示重叠图片：

I need a div with picture bg to overlay an image (with some amount transparency) when hovered on. I need to be able to have one transparent overlay that can be used and reused throughout the site on any image. My first attempt was round-about to say the least. Because I found out you cannot roll-over an invisible div I devised a sandwhich system in which the original image is the first layer, the overlay is the second layer, and the original image is third layer again. This way, when you roll-over, the original image disappears revealing the overlay image over the original image:

http://www.nightlylabs.com/uploads/test.html

所以有用。 Kinda。因为你不能与可见性交互：不可见元素（为什么?!）翻转闪烁，除非你将光标停在它上面。

So it works. Kinda. Because of you cannot interact with an visibility:invisible element (why?!) the roll-over flickers unless you rest the cursor on it.

任何帮助？