<html>
<head>
<script language='javascript'>
var c = 5; //5 secondi
function countdown(){
if(c) {c--; setTimeout(countdown, 1000);}
else document.getElementById('cambiacontenuto').innerHT ML = "<div>Sostituisco l'immagine</div>";
}
</script>
</head>
<body onload='countdown()'>
<span id='cambiacontenuto'>[img]imm.jpg[/img]</span>
</body>
<html>