使用方法：

1、head引入css文件

<link href="css/style.css" rel="stylesheet" type="text/css" />

2、head引入js文件

<script type="text/javascript" src="js/jquery.js"></script>

3、body引入HTML代碼

<div class="suspension">
	<a class="consult" target="_blank" title="在線客服">
		<div class="suspension-list" style="display:none;">
			<div class="suspension-list-content">
				<ul>
					<li>
						<div href="javascript:;" class="service-phone">
							<span class="info-name">客服熱線</span>
							<span class="info-value">400-888-xxxx</span>
						</div>
					</li>
					<li>
						<div href="javascript:;" class="service-qq">
							<span class="info-name">在線客服</span>
							<span class="info-value">80099xxxx</span>
						</div>
					</li>
					<li class="suspension-list-bottom">
						<div href="javascript:;" class="service-proposal">
							<span class="info-name">投訴與建議</span>
							<span class="info-value">最快10分鐘內回應</span>
						</div>
					</li>
				</ul>
			</div>
		</div>
	</a>
	<a class="cart" title="關注微信公眾賬號">
		<div class="pic">
			<div class="pic-content"></div>
		</div>
	</a>
	<a href="javascript:void(0)" class="back-top" style="display: block;" title="返回頂部"></a>
</div>

<script type="text/javascript">
	$(function() {
		$(".back-top").hide();
		$(".back-top").live("click", function() {
			$('html, body').animate({
				scrollTop: 0
			}, 400);
			return false;
		})
		$(window).bind('scroll resize', function() {
			if ($(window).scrollTop() <= 400) {
				$(".back-top").hide();
			} else {
				$(".back-top").show();
			}
		})
	})
</script>