CSV file download code

Details later,

<?php
if(!empty($_GET['file'])){
    $foo = "some value,another value,last value";
    file_put_contents("File1.csv",$foo);
    @ob_end_clean();
    header("Content-type: application/vnd.ms-excel");
    header("Content-disposition: attachment; filename=File1.csv");
    header("Cache-control: private");
     header('Pragma: private');
     header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
    $new_length = filesize("File1.csv");
    echo $foo;
}else{
    echo "<a href='?file=1'>Click here</a>";
}
?>