jquery操作cookie的小例子

jQuery.cookie = function(name, value, options) { 
        if (typeof value != 'undefined') { // name and value given, set cookie 
            options = options || {}; 
            if (value === null) { 
                value = ''; 
                options.expires = -1; 
            } 
            var expires = ''; 
            if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) { 
                var date; 
                if (typeof options.expires == 'number') { 
                    date = new Date(); 
                    date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000)); 
                } else { 
                    date = options.expires; 
                } 
                expires = '; expires=' + date.toUTCString(); // use expires attribute, max-age is not supported by IE 
            } 
            var path = options.path ? '; path=' + options.path : ''; 
            var domain = options.domain ? '; domain=' + options.domain : ''; 
            var secure = options.secure ? '; secure' : ''; 
            document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join(''); 
        } else { // only name given, get cookie 
            var cookieValue = null; 
            if (document.cookie && document.cookie != '') { 
                var cookies = document.cookie.split(';'); 
                for (var i = 0; i < cookies.length; i++) { 
                    var cookie = jQuery.trim(cookies[i]); 
                    // Does this cookie string begin with the name we want? 
                    if (cookie.substring(0, name.length + 1) == (name + '=')) { 
                        cookieValue = decodeURIComponent(cookie.substring(name.length + 1)); 
                        break; 
                    } 
                } 
            } 
            return cookieValue; 
        } 
    }; 
    function getcookie(name) { 
    var cookie_start = document.cookie.indexOf(name); 
    var cookie_end = document.cookie.indexOf(";", cookie_start); 
    return cookie_start == -1 ? '' : unescape(document.cookie.substring(cookie_start + name.length + 1, (cookie_end > cookie_start ? cookie_end : document.cookie.length))); 
    } 
    function setcookie(cookieName, cookieValue, seconds, path, domain, secure) { 
        var expires = new Date(); 
        expires.setTime(expires.getTime() + seconds); 
        document.cookie = escape(cookieName) + '=' + escape(cookieValue) 
                                                + (expires ? '; expires=' + expires.toGMTString() : '') 
                                                + (path ? '; path=' + path : '/') 
                                                + (domain ? '; domain=' + domain : '') 
                                                + (secure ? '; secure' : ''); 
    }