function smallScreen() {
	if (window.getSize().y < 800) {
		$('footer').addClass('small_screen');
		$('sub_footer').addClass('small_screen');
	}
	else {
		$('footer').removeClass('small_screen');
		$('sub_footer').removeClass('small_screen');
	}
}

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