In FireFox funziona in InternetExplorer no
codice:
<script language="javascript" type="text/javascript">
function aggiorna() {
	var f = document.getElementById('make');
	var img = "<img src=\"img.php?back="+ f.backg.value + "&prg=" + f.prg.value + "&info=" + f.info.value;
		if(document.all) {
			document.all.imma.innerHTML=img;
		} else {
			document.getElementById('imma').innerHTML=img;
		}
	}
</script>

<div id="imma">[img]img.php[/img]</div>