function startup()
{ show_onair();
  onair_roller();
}

var onair_id = 'on_air';
var onair_input_id = 'on_air_input';

function show_onair()
{ var url = '/onair.php';
  var params = 'xml=1';
  var ajax = new Ajax.PeriodicalUpdater({success: onair_input_id},
                                        url, 
                                        {method: 'post', parameters: params, onFailure: onair_report}
                                        );
  ajax.frequency = 30;
}

function onair_report(request)
{ $(onair_input_id).innerHTML = "AJAX error: " + request.responseText;
}

var onair_text = ' ';
var onair_array = new Array(' ');
var onair_length = 30;

function onair_roller()
{ var elem = $(onair_input_id);
  if (elem.innerHTML != onair_text)
  { onair_text = elem.innerHTML;
    onair_array = new Array(onair_text.length + onair_length);
    for (var i = 0; i < onair_text.length; i++)
      onair_array[i] = onair_text.charAt(i);
    for (var i = onair_text.length; i < onair_array.length; i++)
      onair_array[i] = '&nbsp;';
  }
  var c = onair_array[0];
  var s = '';
  for (var i = 0; i < onair_array.length-1; i++)
  { onair_array[i] = onair_array[i+1];
    if (i < onair_length+1)
      s += onair_array[i];
  }
  onair_array[onair_array.length-1] = c;
  $(onair_id).innerHTML = s;
  setTimeout("onair_roller()",300);
}