When I use smart blog it always show only default author name my code is as follows

@{
    // Get this blogs root, does not use an id because there may be more thanone blog
    dynamic blogRoot = CurrentPage.AncestorOrSelf("SmartBlogBlog");
    // Get the posts in this blog
    dynamic posts = blogRoot.Descendants("SmartBlogPost");
    //List of authors
    List<string> authors = new List<string>();
    System.Xml.XmlDocument document = new System.Xml.XmlDocument();

    document.Load(AppDomain.CurrentDomain.BaseDirectory + "/config/SmartBlog.config");

    // Loop through the posts to retrieve the authors and generate a list without duplicating them.
    foreach(dynamic post in posts)
    {
        string author = post.author.Length > 0 ? post.author.ToString() : document.GetElementsByTagName("defaultAuthor")[0].InnerText;

        if(!authors.Contains(author))
        {
            authors.Add(author);
        }
    }

    <span class="smartSubTitle smartTopBorder">Authors</span><br />

    // Loop through the generated authors list and add them tothe page
    foreach(string author in authors)
    {
        <a href="@Umbraco.NiceUrl(blogRoot.Id)?author=@author">@author</a><br />
    }
}

i always get default author name but i have many authors name in authors.please help me how can i solve this issue