var refresh_time = 30000;
function do_refresh() {
	$.get('/comm/online.html?t=' + (new Date().getTime()), replace_content);
	setTimeout("do_refresh()", refresh_time);
}
function replace_content(data) {
	document.getElementById('comm').innerHTML = data;
	var e = document.getElementById("refresh_time");
	if (e) {
		refresh_time = e.value;
	}
}