Paypal Payflow FAILURE: Invalid account number [23] - php

Question

I want to implement Paypal Payflow on my Web Application, i am using PHP language as backend. Since Paypal Payflow SDK has support only for .NET and Java i need to implement myself manually with curl calls.
My code for making a request to Paypal Payflow is following:
$user = 'user1'; // API User Username
$password = '123456'; // API User Password
$vendor = 'mainvendor'; // Merchant Login ID
$cardno=str_replace(' ', '', $_POST["cardNumber"]);
$expdate=str_replace(' ', '', $_POST["cardExpiry"]);
$cvv2=$_POST["cardCVC"];
// Reseller who registered you for Payflow or 'PayPal' if you registered
// directly with PayPal
$partner = 'PayPalCA';
$amount = $_POST["amountcurrency"];
$currency = $currencies["currency"];
$url ='https://payflowpro.paypal.com';
$request = 'USER=' . urlencode($user);
$request .= '&VENDOR=' . urlencode($vendor);
$request .= '&PWD=' . $password;
$request .= '&PARTNER=' . urlencode($partner);
$request .= '&TRXTYPE=S';
$request .= '&TENDER=C';
$request .= '&ACCT=' . str_replace(' ', '', $cardno);
$request .= '&EXPDATE=' . $expdate;
$request .= '&CVV2=' . $cvv2;
$request .= '&AMT=' . $amount;
$request .= '&CURRENCY=' . $currency;
$request .= '&COMMENT1=Bet Deposit';
$request .= '&BILLTOFIRSTNAME=' . $userinfo["user_name"];
$request .= '&BILLTOLASTNAME=' . $userinfo["user_surname"];
$request .= '&BILLTOSTREET=' . $userinfo["street_number"];
$request .= '&BILLTOCITY =' . $userlocation->cityname;
$request .= '&BILLTOSTATE =' . $userlocation->subcountryname;
$request .= '&BILLTOZIP=' . str_replace(' ', '',
$userinfo["postal_code"]);
$request .= '&BILLTOCOUNTRY=' . $userinfo["country"];
$request .= '&CUSTIP=' . $iusers->get_ip_address();
$request .= '&EMAIL=' . $userinfo["user_email"];
$headers = array();
$headers[] = 'Content-Type: application/x-www-form-urlencoded';
$headers[] = 'Content-Length: ' . strlen($request);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $request);
curl_setopt($ch, CURLOPT_HEADER, $headers);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($ch);
curl_close($ch);
// Parse results
$response = array();
$result = strstr($result, 'RESULT');
$valArray = explode('&', $result);
foreach ($valArray as $val) {
$valArray2 = explode('=', $val);
$response[$valArray2[0]] = $valArray2[1];
}
if ($response['RESULT'] == 0) {
echo '<span style="color: white;">SUCCESS!</span>';
} else {
echo '<span style="color: white;">FAILURE: ' . $response['RESPMSG'] . ' ['. $response['RESULT'] . ']</span>';
}
When i make the request i get the following response:
FAILURE: Invalid account number [23]
Can someone help me with this issue?
Thanks in advance.