window.addEvent('domready', function() {

	window.addEvent('resize', function() {
		if ($(window).getSize().x <= 820) {
			$('page').setStyles({
				'background-position': 'top left',
				'background-attachment': 'scroll'
			});
		} else {
			$('page').setStyles({
				'background-position': 'top center',
				'background-attachment': 'fixed'
			});
		}
	});

});