Выполнение запроса прошло успешно
-------------------------------------------

if (isset($_POST['author']) &&
    isset($_POST['title']) &&
    isset($_POST['category']) &&
    isset($_POST['year']) &&
    isset($_POST['year']))
{
$author = get_post('author');
$title = get_post('title'); 
$category = get_post('category');
$year = get_post('year');
$isbn = get_post('isbn');

if (isset($_POST['delete']) && $isbn != "")
{
$query = "DELETE FROM classics WHERE isbn='$isbn'";

if (!mysql_query($query.$db_server))
echo "Сбой при удалении данных: $query<br />" .
mysql_error() . "<br /><br />";
}
else
{
$query = "INSERT INTO classics VALUES"
"('$author', '$title', '$category', '$year', '$isbn')";

if(!mysql_query($query, $db_server))
echo "Сбой при вставке данных: $query<br />" .
mysql_error() . "<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";
$result=mysql_query($query);

if (!$result) die ("Сбой при доступе к базе данных: " . mysql_error());
$rows=mysql_num_rows($result);

for ($j=0; $j<$rows; ++$j)
{
$row=mysql_fetch_row($result);
echo <<<_END
<pre>
Author $row[0]
Title $row[1]
Category $row[2]
Year $row[3]
ISBN $row[4]
</pre>
<form action="sqltest.php" method="post">
<input type="hidden" name="delete" value="yes" /> 
<input type="hidden" name="isbn" value="$row[4]" />
<input type="submit" value="DELETE RECORD" /></form>
_END
}
mysql_close($db_server);

function get_post($var)
{
return mysql_real_escape_string($_POST[$var]);
}
?>