var activeItem=null;
function seleciona(id, cls)
{
  var c = document.getElementById('id_content');
  var a = document.getElementById(id);
  
  if (activeItem)
    activeItem.parentNode.className = activeItem.parentNode._className;
  
  if (a)
  {
    if (!a.parentNode._className)
    a.parentNode._className = a.parentNode.className;
    
    a.parentNode.className = 'link ' + cls + '-ativo ativo';
    c.className = 'content-active';
    
    activeItem = a;  
  }
  else
  {
    c.className = 'content';
  }
  
  document.getElementById("frame1").focus();
}