Hi, I am using interbase 6.
I have a problem.
I can't use while do loop in stored procedure.
There is an example in interbase 5 book for while do loop.
When I run this stored procedure, I get a message that ('Unknown Error')

I fined this procedure in the mail list.
I compiled it.
And I Run it.

Select * from Get_Week ('01.01.2001')
I get a massage that ('Unknown error').
And there isn't any result set.

CREATE PROCEDURE GET_WEEK
(
D TIMESTAMP
)
RETURNS
(
WEEK_NO VARCHAR(8)
)
AS
declare variable DAYNUM INTEGER;
declare variable WK1BEGINS DATE;
declare variable YEARNUM INTEGER;
declare variable YEAR_BEGINS DATE;
declare variable WEEKSTR CHAR(2);
declare variable WEEKNUM integer;
declare variable WEEK1_FOUND char(1);
BEGIN
YEARNUM = EXTRACT (YEAR FROM D);
WEEK1_FOUND = 'F';
WHILE (WEEK1_FOUND <> 'T') DO
BEGIN
WK1BEGINS = CAST('01/01/'||CAST(YEARNUM AS CHAR(4)) AS DATE);
while (EXTRACT(WEEKDAY FROM WK1BEGINS) <> 1) DO
WK1BEGINS = WK1BEGINS + 1;
IF (D < WK1BEGINS) THEN
YEARNUM = YEARNUM -1;
ELSE
WEEK1_FOUND = 'T';
END
WEEKNUM = CAST(((D-WK1BEGINS)/7)+0.5 AS INTEGER);
IF (WEEKNUM < 10) THEN
WEEKSTR = '0'||CAST(WEEKNUM AS CHAR(1));
ELSE
WEEKSTR = CAST(WEEKNUM AS CHAR(2));
WEEK_NO = CAST(YEARNUM AS CHAR(4))||'/'||WEEKSTR;
END



Have you ever use while do loop.
Example please.