$(function() {
// OPACITY OF BUTTON SET TO 0%
$(".roll").css("opacity","0");
 
// ON MOUSE OVER
$(".roll").hover(function () {
 
// SET OPACITY TO 70%
$(this).stop().animate({
opacity: .9
}, "slow");
},
 
// ON MOUSE OUT
function () {
 
// SET OPACITY BACK TO 50%
$(this).stop().animate({
opacity: 0
}, "slow");
});
});

$(document).ready(function(){

	// hide #back-top first
	$("#back-top").hide();
	
	// fade in #back-top
	$(function () {
		$(window).scroll(function () {
			if ($(this).scrollTop() > 200) {
				$('#back-top').fadeIn();
			} else {
				$('#back-top').fadeOut();
			}
		});

		// scroll body to 0px on click
		$('#back-top a').click(function () {
			$('body,html').animate({
				scrollTop: 0
			}, 800);
			return false;
		});
	});

});