Inlog systeem zonder cookies of sessions

<?
// gebruik de volgende table voor mysql
CREATE TABLE user (
  userid int(11) NOT NULL auto_increment,
  username varchar(12) NOT NULL DEFAULT '' ,
  userpass varchar(32) NOT NULL DEFAULT '' ,
  sesid varchar(32) NOT NULL DEFAULT '' ,
  time int(14) NOT NULL DEFAULT '0' ,
  PRIMARY KEY (userid),
  INDEX userid (userid)
  );

//-------
// ---->> functions.php <<----
//-------

// wijzig dit in je eigen database gegevens
mysql_connect("localhost","root","");
mysql_select_db("test");

function user_check(){
 global $username,$userpass,$gonder,$time;
 $check_user = @mysql_query("SELECT userid FROM user WHERE username = '$username' AND userpass = '".md5($userpass)."'");
 $row = mysql_fetch_array($check_user);
 $userid = $row["userid"];
 if (!empty($userid)) {
 //genereerd de sessie en de tijd wanneer hij ongeldig word
   $sesid = md5(time());
   $time = time() + 360;
   @mysql_query("UPDATE user SET sesid='$sesid',time='$time' WHERE userid='$userid'");
   // in plaats van sessies en cookies gebruik ik sesid
   header("Location:secret.php?sesid=$sesid");
 } else {
  echo die("<center>Fout paswoord of login naam, probeer het <a href=login.php>opnieuw</a>...</center>");
  }
}

function session_check() {
 global $sesid;
 $check_time = @mysql_query("SELECT zaman FROM user WHERE sesid = '$sesid'");
 $time_row = @mysql_fetch_array($check_time);
 $bitis = $time_row["time"];
 if ($bitis < time()){
 die("<center>Timeout! Probeer het <a href=login.php>opnieuw/a>...</center>");
 }
}
?>

//-------
// ---->> login.php <<----
//-------

<?
include("functions.php");
if (!empty($submit)){
user_check();
} else {
	
echo "<form action=login.php method=post>";
echo "<table width=350 border=0 cellpadding=1 cellspacing=0 align=center>";
echo "<tr>";
echo "<td width=200>Login naam :</td><td><input type=text name=username size=15></td>";
echo "</tr>";
echo "<tr>";
echo "<td width=200>Paswoord :</td><td><input type=password name=userpass size=15></td>";
echo "</tr>";
echo "<tr>";
echo "<td width=200> </td><td><input type=submit name=submit value=Inloggen></td>";
echo "</tr>";
echo "</table>";
echo "</form>";

} 

//-------
// ---->> secret.php <<----
//-------
include("functions.php");
// bekijk sessie id en tijd
session_check();
// laat de content zien
echo "<center>Zet je hier geheime pagina neer Vergeet niet \$sesid achter je url's te doen (dus pagina.php?sesid=\$sesid)";
?>