1996 nissan 200sx ser alarm problem

1996 nissan 200sx ser  alarm problem   lose remote and key, have keys now. hen any of the doors, hood and or trunk are opened the alarm goes off

can not shut alarm off with key in driver door, system just times out. purchased aftermarket remotes, followed programming can not get into programming mode....   you can sit in vehicle until alarm goes off ( times out ) u can lock the doors with the door button but when u unlock with dool lock button alarm goes off... seems to be stuck in alarm mode.? 

tried the programming, close all doors lock doors with door button insert key 6 times with in 10 sec, hazard lights should flash   times indicating program mode, will not do that...can not get it to go into program mode,,, suggestions

thanks