> ## Documentation Index
> Fetch the complete documentation index at: https://docs.slm.m1amdocs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# HOA Form Post Parameters

To create a Form Post parameter, simply create an HTML form that contains elements, forms, and widgets whose names follow the examples shown here. The values associated with these names will be dependent upon your customer’s actions or selections in the HTML form.

The following lists examples of HOA Form Post parameters:

```

 in_WebSession_version='3.9'
 vin_WebSession_method='Account_updatePaymentMethod'
 vin_WebSession_vid
 vin_PaymentMethod_type='CreditCard'
 vin_PaymentMethod_accountHolderName
 vin_PaymentMethod_creditCard_account
 // Upon form submission, HOA will validate the value entered in 
 // this field by running a Luhn check. If the check fails, 
 // the customer’s browser will be redirected to your error URL.
  
 vin_PaymentMethod_creditCard_expirationDate='YYYYMM'
 // Upon form submission, HOA will validate the value entered 
 // in this field by making certain the year begins with “20,” and 
 // the month is between 01 and 12. If this check fails, 
 // your customer’s browser will be redirected to your error URL.
 //(full expirationDate takes precedence)
  
 vin_PaymentMethod_creditCard_expirationDate_Month='MM'
 // Upon form submission, HOA will validate the value entered
 // in this field by making certain that the month is between
 // 01 and 12. If this check fails, your customer’s browser will 
 // be redirected to your error URL.
  
 vin_PaymentMethod_creditCard_expirationDate_Year='YYYY'
 // Upon form submission, HOA will validate the value entered
 // in this field by making certain that the year begins with “20.”
 //If this check fails, your customer’s browser will 
 // be redirected to your error URL.
  
 vin_PaymentMethod_nameValues_cvn
 vin_PaymentMethod_billingAddress_name
 vin_PaymentMethod_billingAddress_addr1
 vin_PaymentMethod_billingAddress_addr2
 vin_PaymentMethod_billingAddress_city
 vin_PaymentMethod_billingAddress_district
 vin_PaymentMethod_billingAddress_postalCode
 vin_PaymentMethod_billingAddress_country
 vin_PaymentMethod_billingAddress_phonev
```

If the customer is redirected to your error URL by one of these error checks, be certain to inform them why form submission failed. Then, initiate a new WebSession, and re-present the order form to your customer.

## Private Form Values

To set the `merchantTransactionId` of a `Transaction`, pass a FORM name-value pair to a `WebSession` `NameValuePair` object. For example:

```

{name => 'vin_Transaction_merchantTransactionId', value => 'tx_' . $time}
```

(Notice that the `Transaction` object's `merchantTransactionId` data member is flattened out and prefixed with `vin_`.)

The following lists examples of HOA Private Form values:

`vin_Account_merchantAccountId`

`vin_PaymentMethod_merchantPaymentMethodId`

**Parent topic:**[Working with HOA with Hosted Fields](../topics/Working_with_HOA_with_Ho)


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