pl/pgsql create table

I wonder when doing in a pg/pgsql function somewhat like

    CREATE TABLE tmp as select foo;

I have an error when tmp don't exist ( "table tmp don't exist" ...)

and all is working well when there is a table tmp (no matter the structure
of this table, the new table has a structure according to foo)

Id with

    DROP table tmp_site;
    CREATE table tmp_site as select foo;

Cheers
 __________________________________________
Jacques Massé
Tel. 33 (0)5 57 89 08 11 - Fax 33 (0)5 57 89 08 01