Instruction for setting up Worldpay payment gateway.
Now go to the WorldPay online administration area at http://support.worldpay.com/admin/ Here you need to enter your WorldPay username and password. The type of integration you want is “Select Junior”. This is the default when you setup an account with WorldPay, so leave this as it is. Now at the bottom-right of the screen, choose “Configuration Options”. Set the Merchant's shop URL to the URL of your site.
You want to set the “Callback URL” to point to this location. . . http://www.yoursite.com/thanks.php?gateway=worldpay
While your WorldPay account is in test mode you can use the following Credit Card number for testing purposes:
4000 0000 0000 0002
along with any valid expiration date.