function mostra_td(id) {
    if (document.getElementById) {
        el = document.getElementById(id);
        if (el.style.display == 'none') {
            //document.getElementById('btn' + id).src = 'images/opened_gray_lg.gif';
            el.style.display = '';
        } else {
            //document.getElementById('btn' + id).src = 'images/closed_gray_lg.gif';
            el.style.display = 'none';
        }
    }
}

var inf_uteis = new Array ("a1","a2","a3","a4");
	
function esconde_inf_uteis(){
	if (document.getElementById) {
		for(i=0;i<=inf_uteis.length -1;i++){
			document.getElementById(inf_uteis[i]).style.display = 'none';
		}
	}
}