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

	fade = document.getElementById('overlay-page_fade');
	fade.style.visibility = "hidden";
}

function overlay_open(elem) {
	//var thumbsrc = elem.src;
	var full_img_src = elem.src.replace('_t','_f');
	//filename = thumbsrc.substring(thumbsrc.lastIndexOf('/')+1,thumbsrc.length);
	//alert(full_img_src);
	overlay_html = '<img src=\"'+full_img_src+'\" class=\"overlay_img\" title=\"Click to Close\" style=\"cursor:pointer;\">';
	
	overlay_div = document.getElementById('overlay');
	overlay_div.style.visibility = "visible";
	overlay_div.innerHTML = overlay_html;

	var view1 = new Viewport();

	//alert(view1.windowY);
	//ie 846 //visible part of page //403missing
	//ff,safari 1249
	//alert(window.innerHeight+' '+document.documentElement.clientHeight+' '+document.body.clientHeight);
	//ie undef, 0, 846
	//safari 880, 1249, 880
	//ff 859, 1249, 859
	
	//overlay_div.style.top = (((view1.windowY - 570) / 2) + view1.scrollY) + "px";
	overlay_div.style.top = (((view1.windowY - 570) / 2) + view1.scrollY) + "px";
	overlay_div.style.left = ((view1.windowX - 744) / 2) + "px";

	//overlay_article_div = document.getElementById('overlay_article');
	//overlay_article_div.style.overflow = "auto";

	fade = document.getElementById('overlay-page_fade');
	fade.style.height = view1.pageY + "px";
	fade.style.width = view1.pageX + "px";
	fade.style.visibility = "visible";
	
}