VB FV() Function Syntax

Did you look in the VB help files? There is a complete explanation of the syntax and required variables.
xxxxx COPIED FROM THE HELP FILE xxxxx
Returns a Double specifying the future value of an annuity based on periodic, fixed payments and a fixedinterest rate.

Syntax

FV(rate, nper, pmt[, pv[, type]])

Named arguments:

rate: Req'd. Double specifying interest rate per period. For example, if you get a car loan at an annual percentage rate (APR) of 10 percent and make monthly payments, the rate per period is 0.1/12, or 0.0083.

nper: Req'd. Integer specifying total number of payment periods in the annuity. For example, if you make monthly payments on a four-year car loan, your loan has a total of 4 * 12 (or 48) payment periods.

pmt: Req'd. Double specifying payment to be made each period. Payments usually contain principal and interest that doesn't change over the life of the annuity.

pv: Optional. Variant specifying present value (or lump sum) of a series of future payments. For example, when you borrow money to buy a car, the loan amount is the present value to the lender of the monthly car payments you will make. If omitted, 0 is assumed.

type: Optional. Variant specifying when payments are due. Use 0 if payments are due at the end of the payment period, or use 1 if payments are due at the beginning of the period. If omitted, 0 is assumed.