function show_img(img)
{
	show_img_end()

	var objOverlay = document.createElement("div");
	objOverlay.setAttribute('id', 'overlay');

	var objImg = document.createElement("img");
	objImg.setAttribute('src', img);
	objImg.onclick = function() { show_img_end(); }

	objTitle = document.createElement("span");
	textNode = document.createTextNode("click on the image to close it");
	objTitle.appendChild(textNode);


	objOverlay.appendChild(objImg);
	objOverlay.appendChild(objTitle);
	document.body.appendChild(objOverlay);
}

function show_img_end()
{
	overlay = document.getElementById('overlay');
	if (!overlay) return;

	img = overlay.getElementsByTagName('img')[0]
	overlay.removeChild(img);
	document.body.removeChild(overlay);
}

function set_showing()
{
	if (!document.getElementsByTagName) return;

	var anchors = document.getElementsByTagName('a');

	for (var i=0; i<anchors.length; i++){
		var anchor = anchors[i];
			
		var relAttribute = String(anchor.getAttribute('rel'));
			
		if (anchor.getAttribute('href') && (relAttribute.toLowerCase().match('showing'))){
			anchor.onclick = function () { show_img(this); return false; }
		}
	}
}