title: Bootstrap - Calling a function ONLY when clicking the navbar-toggle button displays the menu items
body: <p>I want to call a JQuery function ONLY when clicking the navbar-toggle button for my navigation bar will show the menu items.</p>
  
  <p>I do NOT want to call the JQuery function when the button hides my menu items.</p>
  
  <p>How can I do this?</p>