title: how to make a checkbox enable/disable based on selection in multiple box
body: <p>I have a multi selection combo box and a checkbox in a form. </p>
  
  <p>I'd like the checkbox to be enabled only when user selects a particular value from the multi selection combo box. </p>
  
  <p>Is this possible to do ...either by javascript or jQuery. I am already using jquery elsewhere. </p>
  
  <p>Example: <a href="http://jsbin.com/ipomu" rel="nofollow noreferrer">http://jsbin.com/ipomu</a></p>
  
  <p>to begin with checkbox will be disabled. it should only be enabled when user clicks on option 2</p>