This is a procedure (trangain) which computes the realized gain for an
investment account using "First In - First Out" (FIFO).  When units
(or shares) are sold, there is a capital gain (or loss) on the sale.  FIFO
uses the first shares purchased to compute the gain on the first sale.  The
next sale uses the earliest purchased remaining un-sold shares to compute
the gain for that sale and so on. For example:

  DATE    SHARES   AMOUNT

  2-2-89    300      750.00     Purchase 300 shares for $750.00
  3-4-89    150      412.50     Purchase 150 shares for $412.50
  9-9-89   -200     -600.00     Sell 200 shares for $600.00

The gain computed on FIFO uses the 300 shares purchased on 2-2-89 at a cost
per share of $2.50 (750 / 300).  The cost of the 200 shares sold on 9-9-89
was $500.00 (200 x 2.50).  The gain on the 9-9-89 sale is $100.00 (600-500).
There are 100 shares of 2-2-89 purchase unsold.

 12-12-89  -200     -450.00     Sell 200 shares for $450.00

The gain on this sale uses the remaining 100 unsold shares of the 2-2-89
purchase and 100 shares of the 3-4-89 purchase to compute the cost.
The cost is (100 x 2.50) + (100 x 412.50/150) = $525.00.  The gain is thus
600.00-525.00 or $75.00.

The process is repeated for all sales to compute the gain for each sale.

This program does these tedious calculation for you.  The procedure trangain
is called with 3 parameters.
  macct   =   The account number of the investment to be analyzed
  s_gain  =   The total gain for the account..returned to calling program
  long    =   Is the account long.  Long means you own the shares
              that are being sold, short (not long) means you are selling
              shares you don't own.

The database file, transact.dbf has a minimum of 5 fields:

  DATE      Date of the transaction
  ACCT      Account number (Charc) assingned to the investment
  UNITS     Number of units (or shares) bought or sold in the transaction
  AMOUNT    $ amount of the purchase (+) or sale (-)
  GAIN      $ amount of the gain realized on the transaction.  This is
              computed by the procedure trangain.

The database file is index on acct+DTOS(date) to order the transactions
in chronological order by account.  I have included one account as an
example.  It happens to be Fidelity Magellan Mutual Fund.

The way I use this procedure is every time I sell shares of an account,
I first REPLACE date,acct,units and amount into transact.dbf.  If the units
are less than 0, (a sale), I then call trangain to compute and enter the
gain into that record.

Enjoy....Peare