在很多项目中，按钮用自定义背景代替默认的按钮背景及文字，这就要求页面重构师，把默认文字隐藏起来。其实不是一个难题，但在IE里，就要用到一点小技巧了！

1.Html code

With the release of IE 7, the consistent use of PNG for Web sites and Web applications moved closer to a reality. However, while recently experimenting with a few concepts that rely heavily on PNG, I discovered IE interprets the gamma (gAMA) data chunk contained within a PNG differently than other browsers. The image will render darker(i have encountered with it,and it takes me some time to fix it.), which can be problematic if you need a GIF or JPG to match the color profile of a PNG.