function trocaClasse(e)
{
    if (typeof(e)=='undefined')
        var e=window.event;
    source=e.target?e.target:e.srcElement;
    if(source.nodeType == 3)
        source = source.parentNode;
    o=source.parentNode;
    if ((o.className == 'fechado') || (o.className=="aberto"))
        o.className=(o.className=="aberto")?"fechado":"aberto";
    else
        window.open(source.href, '_self');
    return false;
}

window.onload=function(){
l=document.getElementById("listahistorico")
for(var i=0;i<l.childNodes.length;i++)
if(l.childNodes[i].nodeType==1)
{
    l.childNodes[i].childNodes[0].onclick=trocaClasse
}
}