Accessing product reviews from sites

Online product reviews are a very good source of information. They can be used to judge a brand or a product. It becomes very difficult to read all the reviews, so we can write a program to get the product reviews. Let's see one of the ways to extract the customer review data from Amazon. For example, let's consider the movie Transformers – Age of Extinction and see the customer reviews:

urll<- 'http://www.amazon.com/gp/video/detail/B00L83TQR6?ie=UTF8&redirect=true&ref_=s9_nwrsa_gw_g318_i1'

First, we get the relevant URL and store it in a variable so that it can be used in the functions. Then, we need to parse the HTML content of the page and save it to the variable doc. In order to do so, we need to import the package XML. Now, the parsed HTML is stored in the variable doc. Please follow the link for more details on the HTML DOM: http://www.w3schools.com/jsref/dom_obj_document.asp. The code is as follows:

library(XML)
doc<- htmlParse(urll...