js读取Cookie值

//读取Cookie值    function getCookie(parameter) {        var reg, allCookie, allCookie2, iLen, iStart, iEnd;        allCookie = document.cookie;        reg = new RegExp(parameter);        if ((allCookie.search(reg) == -1) || (allCookie.indexOf(parameter + "=") < 0)) {            return ""        } else {            iLen = parameter.length;            iStart = allCookie.search(reg) + iLen + 1;            allCookie2 = allCookie.substr(iStart);            iEnd = iStart + allCookie2.search(/;/i);            if ((iStart - 1) == iEnd) {                return allCookie.substr(iStart)            } else {                return allCookie.substr(iStart, iEnd - iStart)            }        }    }