<link href="//netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<form>
<span id="fileselector">
<label class="btn btn-default" for="upload-file-selector">
<input id="upload-file-selector" type="file">
<i class="fa_icon icon-upload-alt margin-correction"></i>upload file
</label>
</span>
</form>