Redirect customers back to your website after a successful transaction

The PostURL property
The location where the customer will be redirected to after a successful transaction is defined in the Order Page ID properties screen:
  1. Click on "Order Pages" in the top menu of the Merchant Menu.
  2. Click on the properties icon to set the page ID properties.

  3. Set the location in the 'PostURL' field.
The Postfields property
To send transaction information to your PostURL, simply add the fields to post in the 'Postfields' property in the following format:
cust_email,cust_phone,total_amount_us,item1_qty (do not use spaces!)
For a complete list of all supported variables click here. Because the transaction is completed you can also use total_amount and total_amount_us and order_num as postfields.
The customer will see a submit button in the order confirmation screen. The 'ContinueButtonLabel' property allows you to set the label on the submit button. And the 'ContinueButtonForcePress' property adds a warning when the customer forgets to click the submit button.

Silent Post: Replace our submit button with your own submit button and dynamic message

How does silent post work
If the Silent Post option is enabled, the postfields will be posted immediately after the transaction. The customer doesn't need to click on a button. The result of the post (the output of your script), will be included in the order confirmation screen.
To use 'Silent Post' you need to include <!--success--> in the response of your script. If this is not found in the response our server assumes that the post was not successful and displays an error message to the customer together with a retry button.
Because the post is done in the background by our server the PostURL is hidden for the customer. This allows you to add an IP check to your script and use the silent post function to start a secure process on your server.
An example
A company sells online tickets. They post their ticket ID in the user1 variable. The PostURL with Silent Post enabled is used to display the button to print the ticket in the receipt page.
Two scripts are involved:
The PostURL contains a link to script A. This script A receives user1 and order_num. Because silent post is used script A can have an IP check. Only posts from the MultiCards server are allowed. This ensures that only MultiCards marks an 'ID' (set in user1) to be paid. Script A needs to mark the ID as paid and adds the order number and a unique pincode.
Script A responds with the following (this will be included in the receipt page):
<form action="location_of_script_B">
<input type=hidden name=ticketid value="value_of_user1">
<input type=hidden name=pincode value="pincode_created_by_script_A">
<input type=submit name=submit value="Print ticket">
</form>
Script B is called by the customer and receives the user1 and pincode values. This script checks if script A has marked the ID as paid and if the pincode is valid. If not, the customer is trying to commit fraud.
Important
Do not make the output of your script too large. Since it will be included in the confirmation screen it can cause problems for customers who have a slow internet connection. The silent post function is only used to retrieve a dynamic message from your server, not to replace the normal submit button.