... If it makes a difference my section has parental controls.
It makes a difference. Parental controls allow for robust control over a user's account. Websites can be specifically restricted or permitted, the amount of time you spend using the Mac can be limited... it's up to them.
Ask your grandfather to allow you to access Netflix.
If he says no, ask your Mom.
Ok thanks. But I just tried it again on apple discussions and it won't let me go to the login screen the message says exactly safari can not open page the URL address because safari can't establish a secure connection to the serve.I figured out my grandfathers password and there are no restrictions on apple or Netflix.
I recall now this was a known bug with managed accounts - secure websites cannot be used even if they were specifically permitted under Parental Controls.
The problem may have been fixed with Mountain Lion but I have not yet personally confirmed this. Read this thread for more information: