<?php
    header("Content-Type: application/xls");
    header("Content-Disposition: attachment; filename=download.xls");
    header("Pragma: no-cache");
    header("Expires: 0");

    require_once 'conn.php';

    $output = "";

    if(ISSET($_POST['export'])){
        $output .="
            <table>
                <thead>
                    <tr>
                        <th>ID</th>
                        <th>Firstname</th>
                        <th>Lastname</th>
                        <th>Address</th>
                        <th>Job</th>
                    </tr>
                <tbody>
        ";

        $query = $conn->query("SELECT * FROM `member`") or die(mysqli_errno());
        while($fetch = $query->fetch_array()){

        $output .= "
                    <tr>
                        <td>".$fetch['mem_id']."</td>
                        <td>".$fetch['firstname']."</td>
                        <td>".$fetch['lastname']."</td>
                        <td>".$fetch['address']."</td>
                        <td>".$fetch['job']."</td>
                    </tr>
        ";
        }

        $output .="
                </tbody>

            </table>
        ";

        echo $output;
    }

?>