<?php
  if(isset($_POST['submit'])) {
        $submitted = true;
        $Firstname = $_POST['FirstName'];
        $LastName = $_POST['LastName'];
        $Username = $_POST['Username'];
        $Email = $_POST['Email'];
        $password = $_POST['Password'];

       $sql = "INSERT INTO User (FirstName, LastName, UserName, Email, Password) VALUES ('".$Firstname."', '".$LastName."', '".$Username."', '".$Email."', '".$password."')";

        $query = $conn->query($sql);

    if($query === TRUE) {

      echo "User added";

    }else {

      echo mysqli_error();

    }


    }
  ?>
</body>
</html>
<?php
  $sql2 = $conn->query("SELECT * FROM User");
    while($UserRow = $sql2->fetch_array()) {
    echo '
          <tr>
                <td>'.$UserRow['UserID'].'</td>
                <td>'.$UserRow['FirstName'].'</td>
                <td>'.$UserRow['LastName'].'</td>
                <td>'.$UserRow['UserName'].'</td>
                <td>'.$UserRow['Password'].'</td>
                <td>'.$UserRow['Email'].'</td>
              </tr>
          ';

    }
?>