title: Removing an option from all other chosen multiple dropdowns, when selected on a particular dropdown
body: <p>I have attached a JS Fiddle link here:</p>
  
  <p><a href="http://jsfiddle.net/p0b4j5o8/18/" rel="nofollow noreferrer">http://jsfiddle.net/p0b4j5o8/18/</a></p>
  
  <p>If you check the fiddle link, you will see that I have written JavaScript/jQuery code (a function named <code>add_mitigator()</code>) in the HTML section.</p>
  
  <p>When I used to write the code in the JavaScript section, Firebug used to trigger an error stating <code>function add_mitigator() isn't defined</code>.
  But when I wrote the same in the HTML section instead, it runs with no problem. I am not much accustomed with JS Fiddle. How can I write a function in <code>function_name()</code> format in the fiddle?</p>
  
  <p>In my JS Fiddle, there is a dropdown (chosen multiple) with options 1 to 10. When I click on the <code>add_mitigator</code> link, it creates/appends a new chosen dropdown.</p>
  
  <p>Suppose I have three dropdowns, then if I select <code>2 from dropdown 1</code>, then the other dropdowns will have 2 removed from their options. When I will unselect the 2 from the first dropdown, then 2 will again  be available in the other two dropdowns. This should act vice-versa. When 2 is selected from any dropdown, then it is unavailable for all other dropdowns.</p>
  
  <p>How can I achieve this?</p>