读写操作

获取cookie

function getCookie(name){
  var arr = document.cookie.match(new RegExp("(^| )")+name+"=([^;]*)(;|$)");
  if(arr != null) return unescape(arr[2]);  
  return null;
}

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();
}

写入cookie

function setCookie(name, value){
  var Days = 30;
  var exp = new Date();
  exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000); //转换为ms;
  document.cookie = name + "=" + value + ";expires=" + exp.toGMTString();
}