Problem with Key.isDown(Key.ENTER)

1

this code now works with an button. but i want with keywords for example ENTER. but i cant do that.

on (press)
{
_root.buton_add.enabled =false;
_root.mix_it();
_root.buton_letter_add();
_root.buton_answer_add(_root.words);
_root.greenn._visible=false;
_root_bluee._visible=false;
_root.passed_it.text="";
for (i=0;i<_root.questions.length;i++)
 {
  if (_root.words==_root.questions*.toUpperCase())
  {
  _root.puan=_root.puan+_root.questions*.length*(_root.index_no+1);
  _root.txtpuan.text=_root.puan;
  _root.temp_timer=_root.temp_timer+_root.questions*.length;
  _root.questions.splice(i,1);
  }
 }
if (_root.questions.length==0)
{
 _root.bitti();
}
 
}

i write like this but it doesnt work. although i hit ENTER, anything happens.

 
buton_add.onKeyDown = function() {
 if (Key.isDown(Key.ENTER)) {
_root.buton_add.enabled =false;
_root.mix_it();
_root.buton_letter_add();
_root.buton_answer_add(_root.words);
_root.greenn._visible=false;
_root_bluee._visible=false;
_root.passed_it.text="";
for (i=0;i<_root.questions.length;i++)
 {
  if (_root.words==_root.questions*.toUpperCase())
  {
  _root.puan=_root.puan+_root.questions*.length*(_root.index_no+1);
  _root.txtpuan.text=_root.puan;
  _root.temp_timer=_root.temp_timer+_root.questions*.length;
  _root.questions.splice(i,1);
  }
 }
if (_root.questions.length==0)
{
 _root.bitti();
}
 }
}

thanks