Using timestamp in function

Hi,

I am using PostgreSQL 7.4 and was trying to log the time each part of a 
function needs. I found a pretty helpful bit of code in the documentation:

http://www.postgresql.org/docs/7.4/static/plpgsql-expressions.html

I used the following function, called inside the another function:

CREATE or replace FUNCTION mylog_test(integer, varchar) RETURNS 
timestamp AS '    DECLARE        n ALIAS FOR $1;        logtxt ALIAS FOR $2;        curtime timestamp;    BEGIN
curtime:= ''now'';        --INSERT INTO logger VALUES ( nextval(''seq_log''), curtime, 
 
substr(logtxt,0,200));        RAISE NOTICE ''TIME: %'',curtime;        RETURN curtime;    END;
' LANGUAGE plpgsql;

I expected, that the variable curtime gets a new time value, each time 
the function is called (at least that is what I understood from the 
documentation). This works fine, if I test it with
SELECT mylog_test(5, 'test');
But as soon as I call the funtion from another function (which I need) 
the variable curtime does not change anymore.

Can anyone tell me why this does not work and does anyone know a 
solution to this?

For test purposes here is a function called test, which does nothing 
else than to call mylog_test(..) and spend some time calculating.

CREATE or replace FUNCTION test() RETURNS text AS '  DECLARE    i integer;    j integer;    k integer;  BEGIN    FOR i
IN1..10 LOOP      PERFORM mylog(3, ''val '' || i);      FOR j IN 1..2000000 LOOP        k:=j;      END LOOP;    END
LOOP;   RETURN ''THE END'';  END;
 
' LANGUAGE 'plpgsql';


SELECT test();

Any help is appreciated

Silke