Ciao.
Codice PHP:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
*{ 
    margin:0px; 
    padding:0px
}
input,textarea{ 
    width:150px
}
textarea{ 
    height:150px 
}
</style>
</head>

<body>
<?php 
function redirect($page){
        $host= $_SERVER['HTTP_HOST'];
        $uri= rtrim(dirname($_SERVER['PHP_SELF']), '/\\');
        $extra= $page;
        header("Location: ");
        exit();
} 
function getPost($key){
        return isset($_POST[$key]) ? $_POST[$key] : null;
    }
function getGet($key){
        return isset($_GET[$key]) ? $_GET[$key] : null;
    }
function formHasPropriety(){
    $hasProperty= true;
    $args= func_get_args();
    foreach($args as $arg){
        if(is_null(getPost($arg))){
            $hasProperty= false;
        }
    }
    return $hasProperty;
}
if (is_null($action=getGet('action'))){
    $action= 'form';
}
if ($action=='form')
{ 
?>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>?action=new_item" method="post" name="frm">
<input name="check_from" type="hidden" value="<?php echo time();?>" />
<input name="title" type="text" maxlength="50" />

<textarea name="description" cols="30" rows="30"></textarea>

<input name="save_item" type="submit" value="Save" />
</form>
<?php 
}
elseif($action=='new_item')
{
    if(formHasPropriety('check_from','title','description','save_item')){
        //validation
        //input filter ie strip_tags 
        echo 'Insert new_item';
    }
    else{
        redirect('404.php');
    }
}
else{
    redirect('404.php');
} 
?>
</body>
</html>
Che ne pensate può andare ?

Conoscete un metodo migliore ; ?

function redirect($page){
$host= $_SERVER['HTTP_HOST'];
$uri= rtrim(dirname($_SERVER['PHP_SELF']), '/\\');
$extra= $page;
header("Location: http://$host$uri/$extra");
exit();
}