focused() method in Prototype

application.js

Element.addMethods({
  focused: function(element) {
    return element === document.activeElement && ( element.type || element.href );
  }
});

$(document).on('mouseleave', 'input.special', function(e, el){
  if (!el.focused() || el.focused().length == 0) {
    el.removeClassName("special-focus");
  }
});