title: Use Jquery validation for validating dropdown selected item
body: <p>I'm using Mvc web application, and I have a simple dropdown in my page. my dropdown has 3 items and I want to check selected item every time it changes.</p>
  
  <p>Currently I'm writing a JavaScript function to handle dropdown "onchange" event. but as you know this event does not fire when you toggle dropdown items by keyboard.</p>
  
  <p>how can I use jquery custom validation in this case ? I want every time my dropdown selected item changes, certain things happen like disabling a textbox.</p>