Get all Sites and SubSites of a SiteCollection

In this function you receive a ArrayList containing all Sites/SubSites of a SiteCollection using 
the SharePoint Webservice Webs.asmx .  

    private ArrayList GetSites(string siteurl)
    {
        SetStatus("Initialize webservice...");
        ArrayList myList = null;
        // reading al the sites and subsites via webservice
        WS_Webs.Webs webs = new WS_Webs.Webs();
        if (chk_DefaultLoggin.Checked)
            webs.Credentials = System.Net.CredentialCache.DefaultCredentials;
        else
        {
            webs.PreAuthenticate = true;
            webs.Credentials = new System.Net.NetworkCredential(txt_UserID.Text, txt_PassWord.Text, txt_domain.Text);
        }
        webs.Url = siteurl + @"/_vti_bin/webs.asmx";
        try
        {
             XmlNode myNode = webs.GetAllSubWebCollection();
            XmlNodeList nodes = myNode.SelectNodes("*");
            foreach (XmlNode node in nodes)
            {
                // only add sites that starts with the given site url
                if ( node.Attributes["Url"].Value.StartsWith(siteurl))
                    myList.Add(node.Attributes["Url"].Value);
            }
        }
        catch (Exception exception1)
        {
            MessageBox.Show(exception1.Message, "Error loading siteinfo", MessageBoxButtons.OK);
            this.SetStatus("Error loading site info");
        }
        finally
        {
            webs.Dispose();  
        }
    }