new function (){
   var _self = this;
   _self.width = 640;//设置默认最大宽度
   _self.fontSize = 100;//默认字体大小
   _self.widthProportion = function(){var p = (document.body&&document.body.clientWidth||document.getElementsByTagName("html")[0].offsetWidth)/_self.width;return p<0.5?0.5:p;};
   _self.changePage = function(){
       document.getElementsByTagName("html")[0].setAttribute("style","font-size:"+_self.widthProportion()*_self.fontSize+"px !important");
   }
   _self.changePage();
   window.addEventListener("resize",function(){_self.changePage();},false);
};