Quick And Dirty:
<?
if($action=="post")
{
$fp = fopen ("data", "a+");
fputs ($fp, "\n\n%%$name:\n" . htmlentities ($comments));
fclose ($fp);
}
$fp = fopen ("data", "r");
while ($d = fgets ($fp, 2048))
{
if (preg ("/%%([:])+:$/", $d, $M))
echo "<hr>\n<b>Name:</b> $M[1]<p>\n";
else
echo $d;
}
fclose ($fp);
echo "\n<hr>\n<form action='$PHP_SELF' method='POST'>\n<h2>New Post</h2>\nName: <input type='text' name='name'>\n<textarea wrap='off' name='comments' cols=50 rows=20></textarea>\n<p>\n<input type='hidden' name='action' value='post'>\n<input type='submit' value='Post Message'>\n</form>";
?>