<form action="gbook/gbook_add.php" method="post">

<p><input type="text" name="username" size="30" /> Ваше Имя</p>
<p><input type="text" name="email" size="30" /> Ваш E-Mail</p>
<p><textarea name="message" rows="10" cols="40"></textarea></p>
<p><input type="submit" name="send" value="Добавить сообщение" /></p>

</form>

<?php header('Content-Type: text/html; charset=UTF-8', true); // Кодировка для страницы
$filename = "messages.dat";
$delitmer = "<|-|>";
$username_limit = 50;
$email_limit = 80;
$message_limit = 5000;

if (isset($_POST))
{
    if (isset($_POST['username']) & isset($_POST['email']) & isset($_POST['message']))
    {
         if (((strlen($_POST['username'])>0) & (strlen($_POST['username'])<=$username_limit)) &
            ((strlen($_POST['email'])>0) & (strlen($_POST['email'])<=$email_limit)) &
            ((strlen($_POST['message'])>0) & (strlen($_POST['message'])<=$message_limit)))
            {
                $username = str_replace("\r\n", "<br />", htmlspecialchars($_POST['username']));
                $email = str_replace("\r\n", "<br />", htmlspecialchars($_POST['email']));
                $message = str_replace("\r\n", "<br />", htmlspecialchars($_POST['message']));
                $arr = array($username, $email, $message, date("d.m.Y"));
                $new_message = implode($delitmer, $arr) . "\r\n";
                $messages_arr = @file($filename);
                $messages_str = $new_message;
                $messages_str .= trim(implode("", $messages_arr));

                $fp = fopen($filename, "w+");
                fwrite($fp, $messages_str);
                fclose($fp);
                
                echo "Ваше сообщение добавленно!<br />";
				echo "<a href=\"\">Назад</a>";
            }
            else
            {
                echo "Ошибка!!!<br>Не все данные введенны, либо в одном из полей формы слишком много символов.";
            }
    }
}
?>

<h2>Гостевая книга</h2>
<?php
require 'gbook/show_message.php';
require 'gbook/form.php';
?>

<?php
$filename = "gbook/messages.dat";
$delitmer = "<|-|>";
$shablon = '
<p><b>Пользователь: %username%</b></p>
<p>%message%</p>
<p>%add_date%</p>
<br />';


$data = @file($filename);

foreach($data as $val)
{
  list($username, $email, $message, $date) = explode($delitmer, trim($val));
  $tmp_message = str_replace("%username%", $username, $shablon);
  $tmp_message = str_replace("%email%", $email, $tmp_message);
  $tmp_message = str_replace("%message%", $message, $tmp_message);
  $tmp_message = str_replace("%add_date%", $date, $tmp_message);
  echo $tmp_message;
}
?>