//写cookies函数
  //两个参数，一个是cookie的名称，一个是值
  function SetCookie(name,value)
  {
    var Days = 30; //此 cookie 将被保存 30 天
    var exp  = new Date();    //new Date("December 31, 9998");
    exp.setTime(exp.getTime() + Days*24*60*60*1000);
    document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
  }

  //读取cookies函数
  function getCookie(name)
  {
    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
    if(arr != null) return unescape(arr[2]); return "请输入注册时填写的邮箱";
  }

  //删除cookie
  function delCookie(name)
  {
    var exp = new Date();
    exp.setTime(exp.getTime() - 1);
    var cval=getCookie(name);
    if(cval!=null) document.cookie= name + "="+cval+";expires="+exp.toGMTString();
  }
  window.onload=function()
  {
	  $("#email").val(getCookie("userName"));
  }