Код:
<SCRIPT LANGUAGE="JavaScript">

<!-- Begin
var MSIE=navigator.userAgent.indexOf("MSIE");
var NETS=navigator.userAgent.indexOf("Netscape");
var OPER=navigator.userAgent.indexOf("Opera");
if((MSIE>-1) || (OPER>-1)) {
document.write("<BGSOUND SRC=http://javascript.clan.su/mid/5.mid LOOP=INFINITE>");
} else {
document.write("<EMBED SRC=http://javascript.clan.su/mid/5.mid AUTOSTART=TRUE ");
document.write("HIDDEN=true VOLUME=100 LOOP=TRUE>");
}
// End -->
</SCRIPT>