Create tables based on another table

Hi all,

I want to have a table that lists all other tables in a database. For
example:

table Project_List (
project_id integer;
project_name text;
project_type text; -- can have values simple/complex
);

Now I want to automatically create a new table in the database whenever an
entry is made in this "Project_List". Based on "project_type", this new
table could have 2 different structures.

if $project_type is "simple"

create table $project_name ( -- I want this to be filled in
-- from the new row just added
-- in the above table
file_id integer;
file_name text;
);
else

create table $project_name (

file_id integer;
file_name text;
file_chksum text;
);
fi

What mechanism can I use to accomplish this ? Could anyone point me to any
documentation ?

Thanks,
-ansh