C#

public void WhatAreTheDomains()
        {
            try
            {
                DomainCollection domains = Forest.GetCurrentForest().Domains;

                foreach (Domain domain in domains)
                {
                    //Console.WriteLine(domain.Name);
                    if (File.Exists(Environment.CurrentDirectory + "\\Debug.txt"))
                    {
                        MessageBox.Show("WhatAreTheDomains: " + domain.Name);
                    }
                    cboDomains.Items.Add(domain.Name);
                }
            }
            catch
            {
                ErrorLogWriter("We have a problem communicating with the AD");
            }
        }
            public void ShowDomainUsers()
        {
            //string path = "LDAP://xxxx/CN=Users,DC=firm,DC=xxxx,DC=com";
            string Path = "LDAP://" + cboDomains.Text + "/CN=Users,DC=" + Left(cboDomains.Text, (cboDomains.Text.IndexOf(".", 0))) + ",DC=" + Right(cboDomains.Text, (cboDomains.Text.Length - cboDomains.Text.IndexOf(".", 0) - 1));
            string Filter = "(&(objectCategory=person)(objectClass=user))";//(!userAccountControl:1.2.840.113556.1.4.803:=2))";
            string[] PropertiesToLoad = new string[2] { "name", "sAMAccountName" };

            //DirectoryEntry domain = new DirectoryEntry("LDAP://domain.com/CN=Users,DC=Domain,DC=com");
            //LDAP://PeerAssist.com/CN=Users,DC=PeerAssist,DC=com
            try
            {


                if (File.Exists(Environment.CurrentDirectory + "\\Debug.txt"))
                {
                    MessageBox.Show("ShowDomainUsers: LDAP://" + cboDomains.Text + "/CN=Users,DC=" + Left(cboDomains.Text, (cboDomains.Text.IndexOf(".", 0))) + ",DC=" + Right(cboDomains.Text, (cboDomains.Text.Length - cboDomains.Text.IndexOf(".", 0) - 1)));
                }
                using (DirectoryEntry domain = new DirectoryEntry("LDAP://" + cboDomains.Text + "/CN=Users,DC=" + Left(cboDomains.Text, (cboDomains.Text.IndexOf(".", 0))) + ",DC=" + Right(cboDomains.Text, (cboDomains.Text.Length - cboDomains.Text.IndexOf(".", 0) - 1))))
                using (DirectorySearcher searcher = new DirectorySearcher(domain, Filter, PropertiesToLoad))
                using (SearchResultCollection results = searcher.FindAll())
                {
                    foreach (SearchResult result in results)
                    {
                        string name = (string)result.Properties["name"][0];
                        string winuserlogon = (string)result.Properties["sAMAccountName"][0];

                        //MessageBox.Show(name);
                        //string name1 = (string)result.Properties["sAMAccountName"][1];
                        //MessageBox.Show(name1);

                        //OLD WAY
                        //lbxDomainUsers.Items.Add(name + " | " + winuserlogon);

                        DomainUsers = new DomainUsersClass();
                        DomainUsers.FullUserName = name;
                        DomainUsers.WindowsLogonName = winuserlogon;
                        DomainUsersArray.Add(DomainUsers);
                    }
                }

                for (i = 0; i < DomainUsersArray.Count; i++)
                {
                    lbxDomainUsers.Items.Add(((DomainUsersClass)DomainUsersArray[i]).WindowsLogonName);
                }
                
            }
            catch
            {
                MessageBox.Show("We are having a problem with the active directory.");
            }
        }