function RetornaHora(){
    var tmp = document.getElementById("hora").value.split(":");
    var s = tmp[2];    var m = tmp[1];    var h = tmp[0];
    s++;
    if (s > 59){ s = 0;    m++; }
    if (m > 59){ m = 0;    h++; }
    if (h > 23) h = 0;
    s = new String(s); if (s.length < 2) s = "0" + s;
    m = new String(m); if (m.length < 2) m = "0" + m;
    h = new String(h); if (h.length < 2) h = "0" + h;
        
    var temp = h + ":" + m + ":" + s;
    document.getElementById("hora").value = temp;
}
	window.setInterval('RetornaHora()', 1000);