使用Cookie加密存储用户名和密码

                 HttpCookie UserCookie = Request.Cookies["UserCookie"];
                 HttpCookie PwdCookie = Request.Cookies["PwdCookie"];
                 if (UserCookie == null || PwdCookie == null ||
                     UserCookie.Value != CCommons.EncryptDES(strUserCode) ||
                     PwdCookie.Value != CCommons.EncryptDES(strUserPwd))
                {
                
                    UserCookie = new HttpCookie("UserCookie");//存放用户名的cookie
                    PwdCookie = new HttpCookie("PwdCookie");//存放密码的cookie

                    //设置Cookie 永不过期
                    UserCookie.Expires = DateTime.MaxValue;
                    PwdCookie.Expires = DateTime.MaxValue;

                    //加密名和密码并存放在Cooke当中;
                    strUserCode = CCommons.EncryptDES(strUserCode);
                    strUserPwd = CCommons.EncryptDES(strUserPwd);

                    //将数据保存取cookie当中;
                    UserCookie.Value = strUserCode;
                    PwdCookie.Value = strUserPwd;

                    //将新生成的cookie添加到cookies集合当中;
                    Response.Cookies.Add(UserCookie);
                    Response.Cookies.Add(PwdCookie);
}

js文件：
// JScript 文件

 function getCookieValue()
  {
    var allcookies = document.cookie;
    var cookie_User = allcookies.indexOf("UserCookie");
    var cookie_Pwd = allcookies.indexOf("PwdCookie");
    if (cookie_User != -1 && cookie_Pwd !=-1)
    {
        // 把cookie_User放在值的开始，只要给值加1即可。
        cookie_User += "UserCookie".length + 1;
        var cookie_UserEnd = allcookies.indexOf(";", cookie_User);
        if (cookie_UserEnd == -1)
        {
            cookie_UserEnd = allcookies.length;
        }
        var UserValue = unescape(allcookies.substring(cookie_User, cookie_UserEnd));
        
        
         // 密码的Cookie
        cookie_Pwd += "PwdCookie".length + 1;
        var cookie_PwdEnd = allcookies.indexOf(";", cookie_Pwd);
        if (cookie_PwdEnd == -1)
        {
            cookie_PwdEnd = allcookies.length;
        } 
        var PwdValue = unescape(allcookies.substring(cookie_Pwd, cookie_PwdEnd));
        
        SendAjax(UserValue,PwdValue);
     
    }else