The requested URL was not found on this server. Kак исправить?

Question

[fapchat]

код

<?php // sqltest.php
  require_once 'login.php';
  $conn = new mysqli($hn, $un, $pw, $db);
  if ($conn->connect_error) die("Fatal Error");

  if (isset($_POST['delete']) && isset($_POST['isbn']))
  {
    $isbn   = get_post($conn, 'isbn');
    $query  = "DELETE FROM classics WHERE isbn='$isbn'";
    $result = $conn->query($query);
    if (!$result) echo "DELETE failed<br><br>";
  }

  if (isset($_POST['author'])   &&
      isset($_POST['title'])    &&
      isset($_POST['category']) &&
      isset($_POST['year'])     &&
      isset($_POST['isbn']))
  {
    $author   = get_post($conn, 'author');
    $title    = get_post($conn, 'title');
    $category = get_post($conn, 'category');
    $year     = get_post($conn, 'year');
    $isbn     = get_post($conn, 'isbn');
    $query    = "INSERT INTO classics VALUES" .
      "('$author', '$title', '$category', '$year', '$isbn')";
    $result   = $conn->query($query);
    if (!$result) echo "INSERT failed<br><br>";
  }

  echo <<<_END
  <form action="sqltest.php" method="post"><pre>
    Author <input type="text" name="author">
     Title <input type="text" name="title">
  Category <input type="text" name="category">
      Year <input type="text" name="year">
      ISBN <input type="text" name="isbn">
           <input type="submit" value="ADD RECORD">
  </pre></form>
_END;

  $query  = "SELECT * FROM classics";
  $result = $conn->query($query);
  if (!$result) die ("Database access failed");

  $rows = $result->num_rows;

  for ($j = 0 ; $j < $rows ; ++$j)
  {
    $row = $result->fetch_array(MYSQLI_NUM);

    $r0 = htmlspecialchars($row[0]);
    $r1 = htmlspecialchars($row[1]);
    $r2 = htmlspecialchars($row[2]);
    $r3 = htmlspecialchars($row[3]);
    $r4 = htmlspecialchars($row[4]);

    echo <<<_END
  <pre>
    Author $r0
     Title $r1
  Category $r2
      Year $r3
      ISBN $r4
  </pre>
  <form action='sqltest.php' method='post'>
  <input type='hidden' name='delete' value='yes'>
  <input type='hidden' name='isbn' value='$r4'>
  <input type='submit' value='DELETE RECORD'></form>
_END;
  }

  $result->close();
  $conn->close();

  function get_post($conn, $var)
  {
    return $conn->real_escape_string($_POST[$var]);
  }
?>

<?php // login.php
 $hn = 'localhost';
 $db = 'publications';
 $un = 'fapchat'; // Change this
 $pw = 'password'; // Change this
?>

эти 2 файла в 1 папке

вот сам сайт

Когда нажимаю 1 из кнопок