C# LDAP class

public class LDAP
    {
        private string _login;
        private string title;
        private string name;
        private string mail;
        private string id;
        private string firstname;
        private string lastname;
        private string employeetype;
        private string description;
        private string manageruid;
        private string employeenumber;
        private string telephonenumber;


        public string Login { get { return _login; } }
        public string Title { get { return title; } }
        public string Name { get { return name; } }
        public string Mail { get { return mail; } }
        public string ID { get { return id; } }
        public string FirstName { get { return firstname; } }
        public string LastName { get { return lastname; } }
        public string EmployeeType { get { return employeetype; } }
        public string Description { get { return description; } }
        public string ManagerUID { get { return manageruid; } }
        public string EmployeeNumber { get { return employeenumber; } }
        public string TelephoneNumber { get { return telephonenumber; } }

        public LDAP(string login)
        {
            var searchRoot = new DirectoryEntry("LDAP://xxx/ou=active,ou=employees,ou=people,o=xxx");
            searchRoot.AuthenticationType = AuthenticationTypes.Secure;
            var ds = new DirectorySearcher(searchRoot, "(name=" + login + ")", new string[] { "title", "name", "mail", "cn", "employeeNumber", "givenName", "sn", "employeeType", "description", "manageruid", "employeeNumber", "telephoneNumber" });

            var sr = ds.FindOne();
            if (sr == null) return;
            _login = login;
            try
            {
                var de = sr.GetDirectoryEntry();
                if (de.Properties["cn"] != null)
                    name = de.Properties["cn"].Value.ToString();
                if (de.Properties["mail"] != null)
                    mail = de.Properties["mail"].Value.ToString();
                if (de.Properties["title"] != null)
                    title = Strings.ToEachCaps(de.Properties["title"].Value.ToString().Replace('.', ' '));
                if (de.Properties["employeeNumber"] != null)
                    id = de.Properties["employeeNumber"].Value.ToString();
                if (de.Properties["givenName"] != null)
                    firstname = de.Properties["givenName"].Value.ToString();
                if (de.Properties["sn"] != null)
                    lastname = de.Properties["sn"].Value.ToString();
                if (de.Properties["employeeType"] != null)
                    employeetype = de.Properties["employeeType"].Value.ToString();
                if (de.Properties["description"] != null)
                    description = de.Properties["description"].Value.ToString();
                if (de.Properties["manageruid"] != null)
                    manageruid = de.Properties["manageruid"].Value.ToString();
                if (de.Properties["employeeNumber"] != null)
                    employeenumber = de.Properties["employeeNumber"].Value.ToString();
                if (de.Properties["telephoneNumber"] != null)
                    telephonenumber = de.Properties["telephoneNumber"].Value.ToString();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        public LDAP(string login, List<string> fields)
        {
            var searchRoot = new DirectoryEntry("LDAP://xxx/ou=active,ou=employees,ou=people,o=xxx", null, null, AuthenticationTypes.Secure);
            var ds = new DirectorySearcher(searchRoot, "(name=" + login + ")", new string[] { "title", "name", "mail", "cn", "employeeNumber", "givenName", "sn", "employeeType", "description", "manageruid", "employeeNumber", "telephoneNumber" });

            var sr = ds.FindOne();
            if (sr == null) return;
            var de = sr.GetDirectoryEntry();

            _login = login;

            if (fields.Contains("FirstName"))
            {
                firstname = de.Properties["givenName"].Value.ToString();
            }

            if (fields.Contains("LastName"))
            {
                lastname = de.Properties["sn"].Value.ToString();
            }

            if (fields.Contains("Name"))
            {
                name = de.Properties["cn"].Value.ToString();
            }

            if (fields.Contains("Mail"))
            {
                mail = de.Properties["mail"].Value.ToString();
            }

            if (fields.Contains("Title"))
            {
                title = Strings.ToEachCaps(de.Properties["title"].Value.ToString().Replace('.', ' '));
            }

            if (fields.Contains("ID"))
            {
                id = de.Properties["employeeNumber"].Value.ToString();
            }

            if (fields.Contains("EmployeeType"))
            {
                employeetype = de.Properties["employeeType"].Value.ToString();
            }

            if (fields.Contains("Description"))
            {
                description = de.Properties["description"].Value.ToString();
            }

            if (fields.Contains("ManagerUID"))
            {
                manageruid = de.Properties["manageruid"].Value.ToString();
            }

            if (fields.Contains("EmployeeNumber"))
            {
                employeenumber = de.Properties["employeeNumber"].Value.ToString();
            }

            if (fields.Contains("TelephoneNumber"))
            {
                telephonenumber = de.Properties["telephoneNumber"].Value.ToString();
            }
        }

        public static List<LDAP> GetUsers(List<string> logins)
        {
            return logins.Select(login => new LDAP(login)).ToList();
        }

        public static List<LDAP> GetFullNameTitle(List<string> logins)
        {
            var a = new List<string>();
            a.Add("FirstName");
            a.Add("LastName");
            a.Add("Title");
            return logins.Select(login => new LDAP(login, a)).ToList();
        }

        public string GetFullData(char delimiter)
        {
            var result = string.Empty;
                result = "First Name:\t" + firstname + delimiter + "\r\n";
                result += "Last Name:\t" + lastname + delimiter + "\r\n";
                result += "Login:\t\t" + _login + delimiter + "\r\n";
                result += "e-mail:\t\t" + mail + delimiter + "\r\n";
                result += "Title:\t\t" + title + delimiter + "\r\n";
                result += "Manager UID:\t" + manageruid + delimiter + "\r\n";
                result += "Name:\t\t" + name + delimiter + "\r\n";
                result += "ID:\t\t" + id + delimiter + "\r\n";
                result += "Employee Type:\t" + employeetype + delimiter + "\r\n";
                result += "Phone Number:\t" + telephonenumber + delimiter + "\r\n";
                result += "Description:\t" + description + delimiter + "\r\n";
            return result;
        }
    }