Why is my page is looking like this? I am not able to find the problem

Is that all right?
<link rel="stylesheet" href="css/jquery.mobile-1.4.2.min.css">
<link rel="stylesheet" href="css/jquery.mobile-1.4.2.css">
<script type="text/javascript" src="js/jquery-2.1.0.min.js"></script>
<script type="text/javascript" src="js/jquery.mobile-1.4.2.min.js"></script>
<script type="text/javascript" src="js/jquery.mobile-1.4.2.js"></script>
<script type="text/javascript" src="cordova.js"></script>
<script type="text/javascript" src="js/index.js"></script>
HTMl:
<div data-role="header" style="overflow: hidden;">
<h1>I'm a header</h1>
<a href="#" data-icon="gear" class="ui-btn-right">Options</a>
<div data-role="navbar">
<ul>
<li><a href="#">One</a></li>
<li><a href="#">Two</a></li>
<li><a href="#">Three</a></li>
</ul>
</div>
<!-- /navbar -->
</div>