My facebook password keep telling me "your password is incorrect

Hello,
my name is Ashok. i m having some critical problem in facebook. at first i can't open my facebook, but after some point i manage to reset password after getting some code in my email. but whenever i open my facebook it's keep telling me "your password is incorrect" i changed my password so many time with code that i got in email... but it keep telling me "your password is incorrect.., i want to open it also from other browser but it said you put the "old password" Please help....
Thank you