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=../yourhere.mid LOOP=INFINITE>");
} else {
document.write("<EMBED SRC=../yourhere.mid AUTOSTART=TRUE WIDTH=0 HEIGHT=0");
document.write("HIDDEN=true VOLUME=100 LOOP=TRUE>");
}