Does my code look right?

Hi,

Having a few problems with this chunk of code stops page loading, but when removed it works, or when user is logged it it works.

if ( $_GET[sssess] )
{
   session_id( $_GET[sssess] );
}
session_start( );

if ( isset( $_GET[redeempoints] ) && $_GET[redeempoints] == "Y" )
{
   $_SESSION[redeemer] = "Y";
}
if ( $_POST[purchaseorder] )
{
   $_SESSION[po] = "{$_POST['purchaseorder']}";
}
if ( !$_SESSION[loginemail] )
{
   $_SESSION[loginemail] = "noemail";
}
if ( !$_SESSION[adminemail] )
{
   $_SESSION[adminemail] = "noemail";
}
if ( $_POST[discode] )
{
   $_SESSION[discode] = trim( "{$_POST['discode']}" );
}
$auth_ok_check = md5( "{$_SESSION['loginemail']}.{$hash}" );
$admin_ok_check = md5( "{$_SESSION['adminemail']}.{$hash}" );
if ( isset( $_GET['oidref'] ) )
{
   $GLOBALS['_GET']['oidref'] = mysql_real_escape_string( $_GET['oidref'] );
   $sql = "SELECT o_id FROM order_list WHERE ref='".$_GET['oidref']."' AND unh='{$_GET['oidref']}'";
   if ( !( $result = @mysql_query( $sql, $connection ) ) )

   if ( $row = mysql_fetch_array( $result ) )
   {
       $_SESSION['unh'] = $_GET['oidref'];
       header( "location: ".$sshopurl."orderdetails_os.php?o_id={$row['o_id']}" );
       exit( );
   }
   if ( $_SESSION['auth_ok'] == $auth_ok_check )
   {
       header( "location: ".$sshopurl."secure/orders.php" );
       exit( );
   }
   header( "location: ".$sshopurl."secure/login.php?next=orders.php" );
   exit( );
}
if ( preg_match( "/secure/", "{$_SERVER['PHP_SELF']}" ) && !preg_match( "/doqreg.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/qreg.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/voicepaycallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/secpaysecpagecallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/vps_handle_protx_response.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/protx/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/protxformcallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/protxcallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/worldpaycallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/securetradingcallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/barclayscpicallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/paypalcallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/moneybookerscallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/nochexcallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/offlinecallback.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/doregister.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/register.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/doprereg.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/login.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/dologin.php/", "{$_SERVER['PHP_SELF']}" ) )
{
   if ( $auth_ok_check != $_SESSION[auth_ok] )
   {
       header( "Location: ".$sshopurl."secure/login.php?next={$_GET['next']}&shk&p={$_SERVER['PHP_SELF']}" );
       exit( );
   }
   if ( preg_match( "/secure/", "{$_SERVER['PHP_SELF']}" ) )
   {
       $isaccount = "1";
   }
}
if ( preg_match( "/".$adminDir."/", "{$_SERVER['PHP_SELF']}" ) && !preg_match( "/adlogin.php/", "{$_SERVER['PHP_SELF']}" ) || !preg_match( "/forgetful.php/", "{$_SERVER['PHP_SELF']}" ) )
{
   if ( $admin_ok_check != $_SESSION[admin_ok] )
   {
       header( "Location: ".$adminurl."adlogin.php" );
       exit( );
   }
   if ( preg_match( "/".$adminDir."/", "{$_SERVER['PHP_SELF']}" ) )
   {
       $isadmin = "1";
   }
}
$noadirs = count( $admin_dirs );
$i = 0;
for ( ; $i <= $noadirs; ++$i )
{
   if ( !preg_match( "/admin\\/".$admin_dirs[$i]."/", "{$_SERVER['PHP_SELF']}" ) && preg_match( "/".$admin_dirs[$i]."/", "{$_SESSION['admin_type']}" ) )
   {
       continue;
   }
   header( "Location: ".$adminurl."perms.php?noperm={$admin_dirs[$i]}" );
   exit( );
}
if ( !$_SESSION[shopper_type] )
{
   $_SESSION[shopper_type] = "1";
}
if ( $_GET[setcurrency] == 1 )
{
   if ( $_GET[new_currency_id] )
   {
       $GLOBALS['_POST'][new_currency_id] = $_GET[new_currency_id];
   }
   $_SESSION['currency_id'] = $_POST[new_currency_id];
}
if ( $_GET[clearptid] == Y )
{
   session_unregister( "ptid" );
}
if ( $_GET[selectpostage] == 1 )
{
   if ( $_POST[selptid] == Free || $_POST[selptid] == free )
   {
       session_unregister( "ptid" );
   }
   else if ( isset( $_POST[selptid] ) )
   {
       $_SESSION['ptid'] = $_POST[selptid];
   }
   else
   {
       session_unregister( "ptid" );
   }
   $GLOBALS['_POST'][selptid] = mysql_real_escape_string( $_POST[selptid] );
   $sql1 = "UPDATE basket SET ptid='".$_POST['selptid']."' WHERE session_id='".session_id( )."'";
   if ( !( $result1 = @mysql_query( $sql1, $connection ) ) )
   {
       exit( "Couldn't execute request 1" );
   }
}

Thanks