/**
* @author: meizz
* @edit: kimsoft add w+, release object
*/
Date.prototype.format = function(style) {
  var o = {
    "M+" : this.getMonth() + 1, //month
    "d+" : this.getDate(),      //day
    "h+" : this.getHours(),     //hour
    "m+" : this.getMinutes(),   //minute
    "s+" : this.getSeconds(),   //second
    "q+" : Math.floor((this.getMonth() + 3) / 3),  //quarter
    "S"  : this.getMilliseconds(),                 //millisecond
    "w+" : "天一二三四五六".charAt(this.getDay())  //week
  }
  if(/(y+)/.test(style)) style = style.replace(RegExp.$1,
    (this.getFullYear()+"").substr(4 - RegExp.$1.length));
  for(var k in o)if(new RegExp("("+ k +")").test(style))
    style = style.replace(RegExp.$1,
    RegExp.$1.length==1 ? o[k] : 
      ("00"+ o[k]).substr((""+ o[k]).length));
  o = null; //release
  return style;
};