<div class="text" onclick="new Opacity(this,{duration:4.0,from:0.0,to:1})"></div>
2.<div class="text" onclick="new Opacity(this,{duration:4.0,from:1.0,to:0})"></div>来源：http://www.cnblogs.com/rubylouvre/archive/2009/09/14/1566532.html
