function refresh() {
	if (cd.wait > 0) return;
	let img  = document.getElementById("captcha");
	let r    = "mainpage";
	let m    = location.pathname.match(/(\d+).html/);
	if (m) r = `res${m[1]}`;
	let now  = Math.floor(Date.now() / 1000);
	let src  = `/imgboard/captcha.pl?key=${r}&refresh=${now}`;
	img.src  = src;
	countdown(cd.default);
}