i found why %folder% is converted to /, but you can skip the explanation and go for the solution;
the text/function you are editing is actually downloaded by the browser in a static way, and thus downloaded only once.
This is by-design for the default template, it's not a general rule of HFS and other templates can opt to do differently.
All the things that are not so static should be put elsewhere (in the main section, where you read this object will store some %symbols% in the javascript space, so that libs can read them).
But i will not go this way, because we don't actually need %folder% to make it work.
solution:
use this function.
it will work if you the "music" folder is accessible via HFS.
function moveClicked() {
var s = selectedFilesAsStr();
if (!s) return alert('Select something first');
if (!confirm('Are you sure?')) return;
$.post('?mode=section&id=ajax.move', {'dst':'../music/', files:s}, function(res){
var a = res.split(";");
if (a.length < 2)
return alert($.trim(res));
var failed = 0;
var ok = 0;
var msg = "";
for (var i=0; i<a.length-1; i++) {
var s = $.trim(a[i]);
if (!s.length) {
ok++;
continue;
}
failed++;
msg += s+"\n";
}
if (failed)
msg = "{.!We met the following problems:.}\n"+msg;
msg = (ok ? ok+" {.!files were moved..}\n" : "{.!No file was moved..}\n")+msg;
alert(msg);
if (ok) location = location; // reload
});
}//moveClicked