function Popup () {
	window.popup = this;
	this.showing = false;
	this.popup = document.getElementById("popup");
	document.getElementById("popupclose").onclick = function () {
		window.popup.hide();
		return false;
	}
}
Popup.prototype.show = function () {
	if (this.showing) return;
	this.showing = true;
	this.popup.style.display="block";
}
Popup.prototype.hide = function () {
	this.showing = false;
	this.popup.style.display="none";
}