Login probleem

<?
session_start();
if (!isset($HTTP_SESSION_VARS["session_forumaccess"])) {
header("location:inloggen.php");
}
?>

<?
session_start();
if (!isset($HTTP_SESSION_VARS["session_forumaccess"])) {
header("location:inloggen.php");
}
?>

<?
include ("config.php");
if ($actie == "login")
{
session_start();
foreach($_GET as $key => $value)
{
${$key} = $value;
}
foreach($_POST as $key => $value)
{
${$key} = $value;
}
foreach($_SESSION as $key => $value)
{
${$key} = $value;
}
$sql = "select * from users where nick = '$nickname'";
$nick = mysql_query($sql);
while ($record = mysql_fetch_object($nick))
{
$id = $record->id;
$cpupassword = $record->password;
$cpurang = $record->rang;
}
if (($password == "$cpupassword") AND ($nickname != "") AND ($password != ""))
{
$forumaccess = 1;
$session_id = $id;
$session_forumaccess = $forumaccess;
$session_nickname = $nickname;
$session_rang = "$cpurang";
session_register(session_rang);
session_register(session_id);
session_register(session_forumaccess);
session_register(session_nickname);

if (isset($onthouden))
{
setcookie ("cookie_nickname_forum", $nickname, time()+604800);
setcookie ("cookie_password_forum", $password, time()+604800);
}
?>
<meta http-equiv="refresh" content="3; url=javascript:history.go(-2)">
Gegevens correct, u surft terug naar de laatste pagina.
<?
}
else
{
?>
<meta http-equiv="refresh" content="3; url=inloggen.php">
Er is een fout opgetreden bij het inloggen, probeer het opnieuw.
<?
}
}
else
{
// cookie waardes ophalen
$cookie_password = "$HTTP_COOKIE_VARS[cookie_password_forum]";
$cookie_nickname = "$HTTP_COOKIE_VARS[cookie_nickname_forum]";
?>

<script language = "javascript">
function checkFields() {
missinginfo = "";

if (document.form.nickname.value == "") {
missinginfo += "1";
}

if (document.form.password.value == "") {
missinginfo += "1";
}

if (missinginfo != "") {
missinginfo ="__________________________________________________\n" +
"De velden mogen niet leeg zijn!\n" + "__________________________________________________\n PSVZone.nl Forum";
alert(missinginfo);
return false;
}
else
document.form.submit();
}

</script>

<form action = "inloggen.php?actie=login" method = "post" name = "form">
<input type = "hidden" name = "id" value = "<? echo "$id"; ?>"> 
Nickname: 
<input type="text" name="nickname" value = "<? echo "$cookie_nickname_forum"; ?>">
Wachtwoord:</td>
<input type="password" name="password" value = "<? echo "$cookie_password_forum"; ?>">
<input type="checkbox" name="onthouden" value="ja" checked> 
(Mijn gegevens onthouden)
<input type="button" onClick = "checkFields();" value="Inloggen" name="button">
<?
}
?>

<?
include ("config.php");
if ($actie == "login")
{
session_start();
foreach($_GET as $key => $value)
{
${$key} = $value;
}
foreach($_POST as $key => $value)
{
${$key} = $value;
}
foreach($_SESSION as $key => $value)
{
${$key} = $value;
}
$sql = "select * from users where nick = '$nickname'";
$nick = mysql_query($sql);
while ($record = mysql_fetch_object($nick))
{
$id = $record->id;
$cpupassword = $record->password;
$cpurang = $record->rang;
}
if (($password == "$cpupassword") AND ($nickname != "") AND ($password != ""))
{
$forumaccess = 1;
$session_id = $id;
$session_forumaccess = $forumaccess;
$session_nickname = $nickname;
$session_rang = "$cpurang";
session_register(session_rang);
session_register(session_id);
session_register(session_forumaccess);
session_register(session_nickname);
 
if (isset($onthouden))
{
setcookie ("cookie_nickname_forum", $nickname, time()+604800);
setcookie ("cookie_password_forum", $password, time()+604800);
}
?>
<meta http-equiv="refresh" content="3; url=javascript:history.go(-2)">
Gegevens correct, u surft terug naar de laatste pagina.
<?
}
else
{
?>
<meta http-equiv="refresh" content="3; url=inloggen.php">
Er is een fout opgetreden bij het inloggen, probeer het opnieuw.
<?
}
}
else
{
// cookie waardes ophalen
$cookie_password = "$HTTP_COOKIE_VARS[cookie_password_forum]";
$cookie_nickname = "$HTTP_COOKIE_VARS[cookie_nickname_forum]";
?>
 
<script language = "javascript">
function checkFields() {
missinginfo = "";
 
if (document.form.nickname.value == "") {
missinginfo += "1";
}
 
if (document.form.password.value == "") {
missinginfo += "1";
}
 
if (missinginfo != "") {
missinginfo ="__________________________________________________\n" +
"De velden mogen niet leeg zijn!\n" + "__________________________________________________\n PSVZone.nl Forum";
alert(missinginfo);
return false;
}
else
document.form.submit();
}
 
</script>
 
<form action = "inloggen.php?actie=login" method = "post" name = "form">
<input type = "hidden" name = "id" value = "<? echo "$id"; ?>"> 
Nickname: 
<input type="text" name="nickname" value = "<? echo "$cookie_nickname_forum"; ?>">
Wachtwoord:</td>
<input type="password" name="password" value = "<? echo "$cookie_password_forum"; ?>">
<input type="checkbox" name="onthouden" value="ja" checked> 
(Mijn gegevens onthouden)
<input type="button" onClick = "checkFields();" value="Inloggen" name="button">
<?
}
?>