window.addEvent('domready', function(){	size();});
window.addEvent('resize', function(){ size();});
window.addEvent('load', function(){ size();});

function size(){
if($('background') != null){
	var size = window.getSize();
	var background = $('background').getFirst().getSize();

		 if (size.y > background.y){		$('background').addClass('height');	}
	else if(size.x > background.x){		$('background').removeClass('height');	}	
}
}