How to fire event on future dom elements

How to fire event on future dom elements

I cant get my function to fire on elements that are added to dom after domready

       Im trying to remove an input box if it's cleared out by backspace or however                                  
  1.  $(".CC").on("keydown", ".CC", function(){    
  2.   var $this = $(this).val();                  
  3.   console.log($this);                         
  4.   if ($this == "") {                          
  5.   var $id = $(this).attr("id");               
  6.   $("#" + $id).remove();                      
  7.   }                                           
  8.  });                                          

Do not exist during domready

  1.  <input type="text" name="SCCC" class="CC" id="xxx@email1.com" value="xxx@email1.com" size="50" maxlength="50">
  2. <input type="text" name="SCCC" class="CC" id="yyy@email1.com" value="yyy@email1.com" size="50" maxlength="50">