Cookies 常用类方法set,get,clear,getCookieVal

var Cookies = {
    set : function(name, value){
         var argv = arguments;
         var argc = arguments.length;
         var expires = (argc > 2) ? argv[2] : null;
         var path = (argc > 3) ? argv[3] : '/';
         var domain = (argc > 4) ? argv[4] : null;
         var secure = (argc > 5) ? argv[5] : false;
         document.cookie = name + "=" + escape (value) +
           ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
           ((path == null) ? "" : ("; path=" + path)) +
           ((domain == null) ? "" : ("; domain=" + domain)) +
           ((secure == true) ? "; secure" : "");
    },
    get : function(name){
        var arg = name + "=";
        var alen = arg.length;
        var clen = document.cookie.length;
        var i = 0;
        var j = 0;
        while(i < clen){
            j = i + alen;
            if (document.cookie.substring(i, j) == arg)
                return Cookies.getCookieVal(j);
            i = document.cookie.indexOf(" ", i) + 1;
            if(i == 0)
                break;
        }
        return null;
    },
    clear : function(name) {
      if(Cookies.get(name)){
        document.cookie = name + "=" +
        "; expires=Thu, 01-Jan-70 00:00:01 GMT";
      }
    },
    getCookieVal : function(offset){
       var endstr = document.cookie.indexOf(";", offset);
       if(endstr == -1){
           endstr = document.cookie.length;
       }
       return unescape(document.cookie.substring(offset, endstr));
    }
};

cookie 常用操作类方法，备用！