No more talk, just read SecureNet’s document and follow it. Below is the information that extracted from “Gateway Implementation Guide v4 1 5 - 2013-01-07.pdf”

MERCHANT_KEY

GROUP_ID 
SECUREKEY 
SECURENETID

CARD

CARDCODE 
CARDNUMBER 
EXPDATE

INSTALLMENT

AMOUNT 
AUTOCALC_OPTION (A—automatic M—manual)
BALLOON_AMOUNT (Balloon amount)
BALLOON_OPTION (AutoBill offers the capability of the balloon payment to be applied to the first or last payment, as following: 0 - add balloon amount to first payment 1 - add balloon amount to last payment)
COUNT (Number of total installments for installment plan.  1-99.)
REMAINDER_OPTION (AutoBill offers the ability to choose first or last payment if installments are not equally divided, as following: 0 - add remainder to first payment 1 - add remainder to last payment)

RECURRING

AMOUNT (Total value to be charged to the payment method specified.  Include decimal point followed by decimal amount.) 
NOEND_FLAG (0 = Recurring bill has an end date; 1 = Recurring bill has no end date)

OPTIONS

CYCLE 
DAY (Required if CYCLE=M, Q, B, or Y)
FREQUENCY (If CYCLE=M: 1 – 11 (i.e. 2 = every 2 months))

PLAN_AB (This object defines the information that can be submitted to the Gateway for AutoBill transaction processing.)

CUSTOMERID (Contains customer ID associated with payment plan. It cannot be a valid card number.)
INSTALLMENT
MERCHANT_KEY
PAYMENTID (SecureNet Vault Payment ID.  Must be enabled on the account.  It cannot be a valid card number.) 
RECURRING
SCHEDULE (Array of PAYMENT_AB)
STARTDATE (Plan start date. MMDDYYYY.  Verify the date is on or after current date.) 
TYPE (Using the “Recurring AutoBill” payments can be scheduled for daily, weekly, monthly, quarterly, and yearly recurrence.Set TYPE to one of the following: REC—for recurring INS—for installment VAR—for variable.)

TRANSACTION

MERCHANT_KEY
CARD
CHECK
CUSTOMER_BILL
CUSTOMER_SHIP
ENCRYPTION
LEVEL2
LEVEL3
MPI
AUTO
PETROLEUM
HOTEL
PRODUCT
SERVICE
USERDEFINED
SECONDARY_MERCHANT KEY
TERMINAL
HEALTHCARE
IMAGE