Validate a username and password against Active Directory?

using (DirectoryEntry adsEntry = new DirectoryEntry(path, strAccountId, strPassword))

{

    using (DirectorySearcher adsSearcher = new DirectorySearcher(adsEntry))

    {

        //adsSearcher.Filter = "(&(objectClass=user)(objectCategory=person))";

        adsSearcher.Filter = "(sAMAccountName=" + strAccountId + ")";



        try

        {

            SearchResult adsSearchResult = adsSearcher.FindOne();

            bSucceeded = true;



            strAuthenticatedBy = "Active Directory";

            strError = "User has been authenticated by Active Directory.";

        }

        catch (Exception ex)

        {

            // Failed to authenticate. Most likely it is caused by unknown user

            // id or bad strPassword.

            strError = ex.Message;

        }

        finally

        {

            adsEntry.Close();

        }

    }

}