File export datatable not working

ajaykdutta

<link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/1.10.10/css/jquery.dataTables.min.css">
<link rel="stylesheet" type="text/css" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/1.10.10/css/dataTables.bootstrap.min.css">
<link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/buttons/1.1.0/css/buttons.bootstrap.min.css">

$(document).ready(function() { $('#example').DataTable( { dom: 'Bfrtip', buttons: [ 'copy', 'csv', 'excel', 'pdf', 'print' ] } ); } );

Name	Position	Office	Age	Start date	Salary
Name	Position	Office	Age	Start date	Salary
Tiger Nixon	System Architect	Edinburgh	61	2011/04/25	$320,800
Garrett Winters	Accountant	Tokyo	63	2011/07/25	$170,750

What is the fault made by me?