public static bool UserExists(string windowsUserName) { try { using (var ctx = new PrincipalContext(ContextType.Domain, LdapServer, LdapComponent)) { var user = UserPrincipal.FindByIdentity(ctx, windowsUserName); if (user != null) { return(true); } else { return(false); } } } catch (Exception ex) { LoggingHelper.Debug(windowsUserName + " is not authorized!! (" + ex.Message + ")"); return(false); } }