I know this question has been asked here. Basically the solution works but they are using an old version of jquery and the solution was implemented using deprecated functions. So I tried to migrate to the new version, according to answers and questions from this question.
So basically the solution using the old jquery version is this one.
$('textarea.paginate').live('keydown', function(event) {
    if (this.clientHeight < this.scrollHeight) {
        alert("Please Something);
    }
});
This was my migration to the on function, but neither way works. Demo of the example: http://jsbin.com/saxay/1/edit
What I'm doing wrong?
$("textarea").on('keyup','.note-codable',function(event){
  if(event.keyCode == 13) { }
  if (this.clientHeight < this.scrollHeight) {
    alert("Please Something");
  }
});
$(document).on('keyup','.note-codable',function(event){
  if(event.keyCode == 13) { }
  if (this.clientHeight < this.scrollHeight) {
    alert("Please Something");
  }
});
 
     
     
    