var Site = {
	
	// initialisation function
	start : function(){
		var wsize = document.documentElement.clientHeight;
		if ($('container').getHeight() < wsize) {
			var gap = document.documentElement.clientHeight - $('container').getHeight();
			$('lower').setStyle({'height':$('lower').getHeight()+gap + 'px'});
		}
	}
		
};
 
document.observe('dom:loaded', Site.start);