title: JQuery: How to grab what it is selected in the selector
body: <p>I have a box with one select with two options.
  Depending on the options i need to display a different set of checkboxes.
  Depending on what the user choose on the select i will display a set of checkboxes or another.</p>
  
  <p>Here i have made here an example:</p>
  
  <p><a href="http://jsbin.com/acOXisI/20/edit" rel="nofollow">http://jsbin.com/acOXisI/20/edit</a></p>
  
  <p>How can i grab the option selected in the selector?
  And subsequently how can i display or not the checkboxes fieldset?</p>
  
  <p>Thank you very much!</p>