create function syntax question

All,


ver: 6.2.1

Ive looked in all the documentation I can find, however, I keep getting
errors when I try to create function like this.

create function min_max_ave() returns int4 as 'select
min(),max(),(sum()/count()) from routes' language 'sql' ;

I keep getting...
WARN:func_get_detail: function min() does not exist
...but select min() from routes works.

thanks,
wbl
--
"If you're not supposed to eat animals,
why are they made of meat?" :)