problem in paying using paypal

[galtech]

i have a problem in paying using paypal. when i add products the price will be correctly displayed but in paypal the base price is added not the orginal price

code of calculating price

$test=0;
session_start();
$ar20=Db::getInstance()->ExecuteS('SELECT * FROM '._DB_PREFIX_.'price WHERE id="'.$_SESSION['y'].'" ORDER BY size DESC');
for($i=0;$i {
$test=$test+$ar20[$i]['price'];
}
$row['price'] += $test ;

help me................