String to compose and send (in post is better):

$strtoecommerce = $urlecommerce.'?alias='.$alias.'&importo='.$importo.'&divisa=EUR&codTrans='.$codTrans.'&mail='.$mail.'&url='.$url.'&session_id='.$session_id.'&languageID='.$languageID.'&url_back='.$url_back.'&mac='.$mac


Notes:
 1. Payments only in Euros.
 2. Credit card: Visa, MasterCard, AE, Diners, Maestro, Jcb.
 3. To calculate the Md5 (see below) KeyClient Bank assigns a secretkey ($secretkey) to the merchant.
 4. $urlecommerce is the url of the KeyClient server (https).
 5. $alias is the id of the merchant, comunicated by KeyClient.
 6. $importo is the amount to paid; must be without dots and commas and with the last 2 right positions only and always for the decimals (always integers with 2 decimals).
 7. $codTrans is the id, unambiguous, of the order/customer/session/transaction/.. ; can contains from 2 to 30 characters but not the char '#'.
 8. $mail is the mail of customer, whom send the result of payment (facultative).
 9. $url is the url of merchant to whom send the result of payment (#) (facultative).
10. $session_id is the Id of session (facultative).
11. $languageID is the Id of language (*); if omitted is assumed ITA/ENG.
12. $url_back is the url of merchant to whom reenter if the customer aborts the payment in the page of payment of KeyClient bank (#) (facultative).
13. $mac is the message autentication code; this code be compounded applying, with the $secretkey, the MD5 to base64encode of the next string:
	'codTrans='.$codTrans.'divisa=EURimporto='.$importo.$secretkey
 

Variables (example):
$urlecommerce = https://ecommerce.cim-italia.it/ecomm/DispatcherServlet
$alias = payment_xxxxxxx
$importo = 4556 (if the cost of the product bought is €. 45,56)
$codTrans = 1234567890
$mail = nicolas@hikashop.com
$url = http://www.inabox.it/gt/index.php?xxxxxxxxxxxx
$session_id = 123456789
$languageID = ENG
$url_back = http://www.inabox.it/gt/index.php?xxxxxxxxxxxx
$mac = zxcvbzxccvbzxcvbzxcvbzxcvb.........

(*) Languages:
LanguageID	Description
ITA		Italian
ENG		English
SPA		Spanish
FRA		French
GER		German
JPN		Japan
ITA-ENG		Italian/English

(#) return values:
$codTrans = $codTrans sended
$esito = 'ANNULLO' : payment aborted by customer
$esito = 'KO'	   : payment not completed
$esito = 'OK'	   : payment regularly completed
$importo = the amount paid or not
$divisa = EUR
$data = the transaction date (yyyymmdd)
$orario = the time of transaction (hhmmss)
$codAut = Autorization code applied by KeyClient Bank, from 2 to 30 characters
$secretkey = $secretkey sended
$mac = message autentication code; be compounded applying, with the $secretkey, the MD5 to base64encode of the next string:
	'codTrans='.$codTrans.'esito='.$esito.'importo='.$importo.'divisa=EURdata='.$data.'orario='.$orario.'codAut='.$codAut.$secretkey
$session_id = $session_id sended
$BRAND = Credit card used by customer, from 3 to 10 characters
$nome = first name who did the payment, from 1 to 30 characters
$cognome = last name who did the payment, from 1 to 30 characters
$email = email who did the payment, from 1 to 150 characters