function suono(cosa,he,wi){
if (navigator.appName=="Microsoft Internet Explorer"){
document.write('<bgsound src="'+cosa+'" height="'+he+'" width="'+wi+'" loop="infinite">');
document.write('<sound src="'+cosa+'" height="'+he+'" width="'+wi+'">');
}
else{
document.write('<embed src="'+cosa+'" height="'+he+'" width="'+wi+'" loop="true"><noembed>Errore multimediale</noembed></embed>');
}
}

suono('musica4a.mp3',0,0);