<nav>
		<ul>
			<li><a href="#home">Домой</a></li>
			<li><a href="#about">О нас</a></li>
		</ul>
	</nav>
	<div id="home">
		<!-- Some content -->
	</div>
	<div id="about">
		<!-- Some content -->
	</div>

	<script type="text/javascript" src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
	<script>
		$('nav a[href^="#"]').on('click', function() {
			var target = $(this.hash);
			$('html, body').clearQueue().animate({ scrollTop: target.offset().top }, 1500);
			return false;
		});
	</script>