Event.observe(
	window,
	'load',
	function(){
		centerImage();
	}
);
function centerImage(){
	if(!$('openingImage')){
		return;
	}
	var image = $('openingImage').down('img');
	image.style.marginLeft = '-' + Math.floor(image.width/2) + 'px';
	image.style.marginTop = '-' + Math.floor(image.height/2) + 'px';
	image.style.position = 'absolute';
	image.style.top = '50%';
	image.style.left = '50%';
}