up and down key not functioning in i-mode html simulator II

Dear users ,i have following actionscriptcode

Code:

---

var navBtn:Object = new Object();
 navBtn.onKeyDown = function(success)
 { 
  var code:Number = Key.getCode(); 
 //if(code == 40)  
 if(code ==9) 
  {   
    //this works for both up and down keys   
  } 
}

---

What I have is a navigation menu with up and down keys.I have to use 40 for down key press and 38 for up key press.When I do this,it works fine in adobe device central .But it doesn't work on i-mode html simulator.And when I do code ==9 as shown the up and down key works but it works for both up and down keys.
So what should I do to make up and down keys work on i-mode html simulator II .All your help will be greatly appreciated
Thanks in advance