getting last day of month

Hi all.
I need to find out the last day of current month. Currently I do the
trick with code below, but that's rather ugly way to do it IMHO. Could
anybody suggest me a better way ?

The following is my testing procedure :

CREATE or REPLACE FUNCTION test_findout_dates()
RETURNS integer AS $$
DECLARE
begin_date date;
end_date date;
current_month int;
current_year int;
last_day int;
BEGIN
current_month := extract ( month from now() ) ;
current_year := extract ( year from now() ) ;

begin_date := current_year || '-' || current_month || '-01' ;

last_day := 31;
begin
end_date := (current_year || '-' || current_month || '-'||
last_day) :: date;
last_day := 0 ;
exception
when others then
raise notice '31 doesnt cut for month %',current_month ;
end;

if last_day > 0 then
begin
last_day := 30;
end_date := (current_year || '-' || current_month || '-'||
last_day) :: date;
last_day := 0 ;
exception
when others then
raise notice '30 doesnt cut for month %',current_month ;
end;
end if;

if last_day > 0 then
begin
last_day := 29;
end_date := (current_year || '-' || current_month || '-'||
last_day) :: date;
last_day := 0 ;
exception
when others then
raise notice '29 doesnt cut for month %',current_month ;
end;
end if;

if last_day > 0 then
begin
last_day := 28;
end_date := (current_year || '-' || current_month || '-'||
last_day ) :: date;
last_day := 0 ;
exception
when others then
raise notice '28 doesnt cut for month %',current_month ;

end;
end if;

raise notice 'begin date is % ',begin_date;
raise notice 'end date is % ',end_date;

return 1;
END;
$$ LANGUAGE plpgsql ;

Thans in Advance, Sergey.