function insertOverlayCode() {
	$$('body')[0].insert(['',
		'<div id="overlay-background" style="display:none;"></div>',
		'<div id="overlay-holder" style="display:none;">',
		'<div id="overlay-foreground" style="display:none;">',
		'</div>',
		'</div>'
	].join(''));
}
function clearOverlay() {
	$('overlay-foreground').hide();
	$('overlay-background').fade({duration:.5});
	$('overlay-holder').hide();
}
function showOverlay(element, width, height) {
	$('overlay-foreground').setStyle( {
		width: width + 'px',
		left: getOffset('left', width, height) + 'px',
		top: getOffset('top', width, height) + 'px',
		position: 'absolute'
	});
	$('overlay-background').setStyle( {
		height: (document.height || document.body.offsetHeight) + 'px'
	});
	$('overlay-foreground').innerHTML = '<div><a href="javascript:clearOverlay();"><img src="images/buttons/close_button.gif" border="0" width="30" height="30" alt="Close" /></a></div>';
	$('overlay-foreground').innerHTML += '<img src="images/photos/photo_' + element + '.jpg" onClick="clearOverlay();"  />';	
	$('overlay-background').show();
	$('overlay-holder').show();
	$('overlay-foreground').appear({duration:.5});
}
function getOffset(dimension, _width, _height) {
	var ybounds = document.viewport.getHeight();
	var xbounds = document.viewport.getWidth();
	var offset = 0;
	if (typeof(window.pageYOffset) == 'number') {
		offset = window.pageYOffset;
	}
	else if (document.body && document.body.scrollTop) {
		offset = document.body.scrollTop;
	}
	else {
		offset = document.documentElement.scrollTop;
	}
	if (dimension == 'top') {
		var top = Math.floor(( ybounds - _height ) / 2) + (offset - 50);
		return top;
	}
	else {
		var left = Math.floor(( xbounds - _width ) / 2);
		return left;
	}
}