var MSG = "flash";
var FORMAT = "<div class='round'></div><p>%s</p><div class='round'></div>"
var TOP_OFFSET = 100;
var OPACITY = .95;

var _hidding = true;
function showMessage(message)
{
  $(MSG).innerHTML = FORMAT.replace("%s", message);
  $(MSG).setStyle({"top" : TOP_OFFSET + "px"});
  $(MSG).show();
  _hidding = false;
  Event.observe(document, 'keypress', function(event){ hideMessage(); });
  setTimeout("Event.observe(document, 'mousemove', function(event){ hideMessage(); });", 1000);
}

function hideMessage()
{
  if (!_hidding)
  {
    _hidding = true;
    new Effect.Fade(MSG, {duration:.6});
  }
}