Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

Let me give you an example: I've read this book with much expectation, it was very boring all through out the book
The answer to this example can be: Negative
Here is why: Review writer does not like the book because it was boring, therefore it is a negative review.

OK. solve this:
Put new batteries in - product wont turn on at all - very disappointed !!! Save your money - many others are better - should have read the other reviews and then i would have been warned
Answer:
Negative