today = new Date() 
var timer = null

function stop()
{
clearTimeout(timer)
}

function start()
{
today = new Date() 
var oggi = ("Sono le "+today.getHours()+":"+today.getMinutes()+":"+today.getSeconds()+" del "+today.getDate()+"/"+(today.getMonth()+1)+"/"+today.getYear())
document.bruno.mostra_giorno.value = oggi
timer = setTimeout("start()",1000)

}