I agree with Kat's advice. While both the 1976 strain and the 2009 pandemic strain are known as "swine flu" there is enough distinction between them that the 1976 swine flu vaccination does not suffice for the 2009 version.
You should definitley talk to your doctor about whether or not you should get the H1N1 vaccine. There are a number of factors to consider including your age, risk level, health issues, etc. Only your doctor is qualified to give you advice.
That said, the H1N1 vaccine you received in 1976 will not give you immunity to the current strain of H1N1 currently being dealt with. It's called "Novel" H1N1 and has mutated since the 1970's outbreak.
There's lots of great H1N1 info in the Education.com Swine Flu Information Center (link below) Hope this helps!