At Walmart in the movie section there is a big display full of movies only $5, but they also contain $5 Movie Cash to see The Lorax. Make sure the movie package that you pick up has the $5.00 Movie Cash to The Lorax. Then when you open it up you will see the code to enter into THIS website.
Then, after you enter the code then you will get a PDF that contains your movie cash at the bottom. This movie cash does not expire until 5/12, and this may only be at some of the Walmart stores.
Side Note: Save the file (it can only be used once), and print it out.