A plugin was obtained from the following link: http://www.jqueryscript.net/other/jQuery-Plugin-For-Smooth-Scroll-To-Top-Bottom-scrollToTop.html.i and the code was attached below in the index.html file. Several jQuery plugins were attempted, but none worked for me.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=0" />
<title>Pharmaceutical</title>
<link rel="shortcut icon" type="image/x-icon" href="css/images/favi.png" />
<link rel="stylesheet" href="css/style.css" type="text/css" media="all" />
<link href='http://fonts.googleapis.com/css?family=Raleway:400,900,800,700,600,500,300,200,100' rel='stylesheet' type='text/css'>
<link href="http://www.jqueryscript.net/css/jquerysctipttop.css" rel="stylesheet" type="text/css">
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script src="js/jquery.totop.js" type="text/javascript"></script>
<script src="js/jquery-1.8.0.min.js" type="text/javascript"></script>
<!--[if lt IE 9]>
<script src="js/modernizr.custom.js"></script>
<![endif]-->
<script type="text/javascript" src="jquery.js"></script>
<script src="js/jquery.carouFredSel-5.5.0-packed.js" type="text/javascript"></script>
<script src="js/functions.js" type="text/javascript"></script>
</head>
<body>
<!-- wrapper -->
<div id="wrapper">
<!-- shell -->
<div class="shell">
<!-- container -->
<div class="container">
<!-- header -->
<header id="header">
<h1 id="logo"><a href="#">Retina</a></h1>
<!-- search -->
<div class="search">
<form action="" method="post">
<input type="text" class="field" value="keywords here ..." title="keywords here ..." />
<input type="submit" class="search-btn" value="" />
<div class="cl"> </div>
</form>
</div>
<!-- end of search -->
<div class="cl"> </div>
</header>
<!-- end of header -->
<!-- navigaation -->
<div id="menu">
<ul class="menu">
<li><a href="#" class="parent"><span>Home</span></a>
<div><ul>
<li><a href="#"><span>About us</span></a></li>
<li><a href="#" class="parent"><span>History</span></a>
...