dropdownInit = function()
{
  ulMenuItems = document.getElementById('dropdown').getElementsByTagName('LI');
  ulMenuItemsLen = ulMenuItems.length;
  
  for (var i = 0; i < ulMenuItemsLen; i++)
  {
    var menuItem = ulMenuItems[i];

    menuItem.onmouseover = function()
    {
      this.className += ' bbhover';
    }
    
    menuItem.onmouseout = function()
    {
      this.className = this.className.replace(/\s?bbhover$/, '');
    }
  }
}

if (window.addEventListener)
  addEventListener('load', dropdownInit, false);
else if (window.attachEvent)
  attachEvent('onload', dropdownInit);