Given the xml data base of movies below, how do you parse out specific sub-category. For instance, I want to pull a list all the movies that are...

Given the xml data base of movies below, how do you parse out specific sub-category. For instance, I want to pull a list all the movies that are rated PG (Enemy Behind and Ishtar).

<collection shelf="My Movies">

<movie title="Enemy Behind">

  <type>War, Thriller</type>

  <year>2003</year>

  <rating>PG</rating>

  <description>US-Japan war</description>

</movie>

<movie title="Transformers">

  <type>Animated, Science Fiction</type>

  <year>1989</year>

  <rating>R</rating>

  <description>A scientific fiction</description>

</movie>

<movie title="Ishtar">

  <type>Comedy</type>

  <rating>PG</rating>

  <year>1987</year>

  <description>Extreme boredom</description>

</movie>

</collection>