Greetings folks, dumb question maybe?

Hello, I'm a little new at this so please bear with me.

I am trying to create a function that loads 100M test records into a
database, however I am having a hard time building the function that
does so.

I'm trying to do this in PGAdmin III for Ubuntu. Is there something
that I have wrong with this? I know that this works in MySQL (and yes I
know that MySQL bends the SQL Standards), but I am not sure what I am
doing wrong exactly. I am coming up with the error that says there's an
error in my syntax near the v INTEGER := 0 line. I get the same error
in psql as I do in the PGAdmin III.

I have the following so far:

DECLARE
v INTEGER := 0;
BEGIN
while v < 100000000
DO
INSERT INTO unpart_tbl_test VALUES
(v, 'test string data', adddate('1995-01-01', (rand(v)*36520) mod 3652));
v := v + 1;
END WHILE;
END;

Any insight would be greatly appreciated.

- J