You can write below code to get Application object Server name in current session in axapta .
sysClientSessions _ClientSessions;
sysServerSessions _ServerSessions;
select _ServerSessions exists join _ClientSessions where _ClientSessions.SessionId == sessionID()
&& _ClientSessions.ServerID == _ServerSessions.ServerId;
info(substr(_ServerSessions.AOSId, 1, strfind(_ServerSessions.AOSId, '@', 1, strlen(_ServerSessions.AOSId))-1));