jQuery是一款同prototype一样优秀js开发库类，特别是对css和XPath的支持，使我们写js变得更加方便！如果你不是个js高手又想写出优 秀的js效果，jQuery可以帮你达到目的！ -jQuery is a prototype with the same type of outstanding library js development, especially for the css and XPath support, so that we become more convenient to write js! If you are not a js expert js want to write good effect, jQuery can help you achieve the objective!