Unable to create function which takes no arguments

I am a project manager for a popular forum system. We are adding support
for PostgreSQL in the next version (which is currently in beta), and
have added several PostgreSQL functions to emulate MySQL functions of
the same name.

I am trying to create a "UNIX_TIMESTAMP()" function in PostgreSQL, which
will return the current timestamp. However, whenever I try to add this
function in phpPgAdmin, it says 'Syntax error at or near ")" at
character 28'.

This is the SQL I'm using:

CREATE FUNCTION unix_timestamp() RETURNS integer AS '
SELECT current_timestamp()::int4 AS result;
' LANGUAGE SQL;

The documentation indicates that the arguments are optional, and even
shows an example of a function with no arguments. How can I create this
function?
--

Michael Eshom
Christian Oldies Fan
Cincinnati, Ohio