$('document').ready(function() {

		if (navigator.userAgent.search('MSIE 6') > -1) {
			return;
		}

		var scroller = $('<img id="scroller" width=64 height=64 src="/js/img/green_arrow_up.png" alt="UP!" />');
		scroller.css('cursor', 'pointer');
		scroller.css('position', 'fixed');
		scroller.css('display', 'none');
		scroller.appendTo('body');

		var scrollTop;

		if (navigator.userAgent.search('IE') > -1) {
		// IE
			var speed = ''
			var showScroller = function() {
				$('#scroller').show();
			}
		} else {
		// normal browsers
			scroller.css('opacity', '0.7');
			var speed = 'normal';
			var showScroller = function() {
				$('#scroller').fadeIn(speed);
			}
		}

		// scroller positioning
		if ('undefined' == typeof(window.innerHeight)) {
			window.innerHeight = document.documentElement.clientHeight;
			window.innerWidth = document.documentElement.clientWidth;
		}

		$('#scroller').css('top', (window.innerHeight - $('#scroller').height() - 10) + 'px');
		$('#scroller').css('left', (window.innerWidth - $('#scroller').width() - 50) + 'px');

		// scroll by itself
		$('#scroller').click(function() {

			$('body').scrollTo( 0, 1000, {easing:'easeOutCirc'}, {axis:'y'} );

		});

		var moveScroller = function () {
			scrollTop = document.documentElement.scrollTop + document.body.scrollTop;
			if (scrollTop > 500) {
				showScroller();
			} else {
				$('#scroller').hide(speed);
			}
		}

		// show / hide scroller
		moveScroller();
		$(window).scroll(moveScroller);

	}
);