function align_middle()
{
	var class_name = 'verticalAlign';
	var div = $$('div.'+class_name);
	
	if(div.length>0)
	{

		div.each(function(el){
			el.setStyle('visibility','hidden');
			var parent_div = el.getParent();
			var parent_height = parent_div.offsetHeight;
			var el_height = el.offsetHeight;
			var displace = (parent_height - el_height)/2;

			el.setStyle('marginTop', displace);
			el.setStyle('visibility','visible');
		});
	}
}
window.addEvent('domready',function(){ align_middle(); });