/***************************************************

    Common Function

 ***************************************************/
var $ = function(id) {
  return document.getElementById(id);
};

var addEvent = function(obj, ev, handler) {
  if (obj.addEventListener)
    obj.addEventListener(ev, handler, false);
  else if (obj.attachEvent)
    obj.attachEvent('on' + ev, handler);
  else /* Caution! Override */
    obj['on' + ev] = handler;
};

var htmlspecialchars = function(str) {
  return str.replace(/[&"'<>]/g, function($0) {
    if ($0 == "&")  return '&amp;';
    if ($0 == "\"") return '&quot;';
    if ($0 == "'")  return '&#039;';
    if ($0 == "<")  return '&lt;';
    if ($0 == ">")  return '&gt;';
  });
};