ok, danke, das funktioniert:
<HTML>
<BODY>
<input name=start type=submit value="start" onClick=go()>
<input name=stop type=submit value="stop" onMousedown=window.clearInterval(aktiv); onMouseup=window.clearInterval(aktiv);>
</BODY>
<SCRIPT LANGUAGE="JavaScript" type="text/javascript">
m = new Array();
z = 0;
function go() {
aktiv = window.setInterval("s()",1);
}
function dontgo() {
window.clearInterval(aktiv);
}
function s() {
m[z] = document.createElement("embed");
m[z].src = "md/" + z + ".mid";
m[z].autostart = false;
m[z].hidden = false;
m[z].id = z;
document.body.appendChild(m[z]);
z++;
if (z > 47)
window.clearInterval(aktiv);
}
</SCRIPT>
</HTML>