This might be useful for web developer which wants to have one key event handler that compatible with all browsers.

document.onkeyup = KeyCheck;

function KeyCheck(e)
{
  //this is used for cross browser
  var KeyID = (window.event) ? event.keyCode : e.keyCode;

  switch(KeyID)
   {

   case 13:
    checkPostCodeSelection();
    break;
      }
}