function overlay_close() {
	overlay_div = document.getElementById('overlay');
	overlay_div.style.overflow = "hidden";
	overlay_div.style.visibility = "hidden";

	content_div = document.getElementById('page_content');
	
	if (content_div != null) {
		content_div.style.overflow = "auto";
	}
	
	fade = document.getElementById('overlay-page_fade');
	fade.style.visibility = "hidden";
	
}

function overlay_open() {
	overlay_div = document.getElementById('overlay');
	overlay_div.style.overflow = "auto";
	overlay_div.style.visibility = "visible";

	var view1 = new Viewport();

	overlay_div.style.top = (((view1.windowY - 450) / 2) + view1.scrollY) + "px";
	overlay_div.style.left = ((view1.windowX - 610) / 2) + "px";
	
	fade = document.getElementById('overlay-page_fade');
	fade.style.height = view1.pageY + "px";
	fade.style.width = view1.pageX + "px";
	fade.style.visibility = "visible";
	
}