[PHP] Can sombody explain

Hey,

this is my login script

PHP Code:

---

<?php
require_once('sqlconn.php');
    session_start();
    
    if(!get_magic_quotes_gpc()) {
        $login=mysql_real_escape_string($_POST['login']);
    }else {
        $login=$_POST['login'];
    }

    $qry="SELECT member_id FROM members WHERE login='$login' AND passwd='".md5($_POST['password'])."'";
    $result=mysql_query($qry);
    if($result) {
        if(mysql_num_rows($result)>0) {
            session_regenerate_id();
            $member=mysql_fetch_assoc($result);
            $_SESSION['SESS_MEMBER_ID']=$member['member_id'];
            session_write_close();
            header("location: ../index.php");
            exit();
        }else {
            header("location: ../index.php?action=failed");
            exit();
        }
    }else {
        die("Query failed");
    }
?>

---

can sombody explain me, what this actualy do?

PHP Code:

---

if(!get_magic_quotes_gpc()) {
        $login=mysql_real_escape_string($_POST['login']);
    }else {
        $login=$_POST['login'];
    } 


---

If (magic quotes function is available)
{
$login = strip_harmfull_characters($login);
}
else
{
$login = do_nothing($login);
}

Hope this pseudo-code makes sense.