php实现简单的留言板程序

<?php

define("USERS_LOG","users.log");

if($_SERVER["REQUEST_METHOD"] == "POST"){
$fn = trim(strip_tags($_POST["fname"]));  
$ln = trim(strip_tags($_POST["lname"])); 
$user = "$fn $ln \n";
file_put_contents(USERS_LOG,$user, FILE_APPEND);
header("Location: test.php");
exit;
}
?>

<form  action="" method="post">
<input type='text' name='fname'>
<input type='text' name='lname'>
<input type='submit' value='submit it'>

</form>

<?php
if(file_exists(USERS_LOG)){

    $users = file(USERS_LOG);
    if(is_array($users)){
        $users = array_reverse($users);
        echo "<ol>";
        foreach ($users as $user){
            echo "<li>$user</li>";
        }
        echo "</ol>";
    }

}
?>