Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.
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Question: I bought this air mattress to use while my new bed was being shipped from back east, the bed lost air every night and I woke up almost on the floor. I tried to send it back but it was impossible to get back into the box.

Answer: Negative

Question: This DVD is one of my all time favorite musical DVDs. Miss Jackson proves why she is the highest paid singer in the industry. With a combination of costume changes, great choreography, Janet's greatest hits, and a sold out crowd at Madison Square Garden, the DVD makes for an excellent night of entertainment. I only regret that I was not able to see the concert in person here in my home town due to a cancelation of the concert;however, the DVD is definately a suitable substitute. I highly recommend this DVD to any fans of Janet, lovers of music, and owners of quality DVDs.

Answer: Positive

Question: This is my first Dean Koontz novel and it will surely not be my last.Frankenstein, Book one: Prodigal Son is a refreshing tale of what happens when the man becomes the monster and the monster becomes the man. Mix that in with a few serial killers, clones and a unlikely partenrship. Think James Paterson meets Mary Shelly.Already on Book 2 can't wait to see what happens next.

Answer:
Positive