Grandsons are viewing adult content...help me stop it

I have long since lost the manual for my Sharp tv but I need to reset my passcode! I overheard my young grandsons talking about adult programming they had watched while spending the night at my house :( Tried to program parental controls but I don't remember the 4 digit code I once used...can you help?? The model number is 19R-M100, manufactured in August 2003.