function isJsEnabled() {
  if (typeof document.jsEnabled == 'undefined') {
    // Note: ! casts to boolean implicitly.
    document.jsEnabled = !(
     !document.getElementsByTagName ||
     !document.createElement        ||
     !document.createTextNode       ||
     !document.documentElement      ||
     !document.getElementById);
  }
  return document.jsEnabled;
}


if (isJsEnabled()) {
  document.documentElement.className = 'js';
}

function addLoadEvent(func) {
  var oldOnload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  }
  else {
    window.onload = function() {
      oldOnload();
      func();
    }
  }
}

function addUnLoadEvent(func) {
  var oldOnUnload = window.onunload;
  if (typeof window.onunload != 'function') {
    window.onunload = func;
  }
  else {
    window.onunload = function() {
      oldOnUnload();
      func();
    }
  }
}