Help with functions

I'm having trouble trying to create a function.  I'm new to functions and
I'm trying to figure them out but I can't even get something simple like
this to work.  I believe I should be able to do 'SELECT getprice('text1',
'text2', 'text3', 'text4') as price' but all I get in PGAdmin tool is syntax
error near getprice.  Is my SELECT statement wrong or my function.  I did a
createlang on plpgsql before I started.  I'm running 7.2.4.

CREATE FUNCTION getprice(text, text, text, text) RETURNS float8 AS 'DECLARE
   v_itemnum ALIAS FOR $1;
   v_custnum ALIAS FOR $2;
   v_pcid ALIAS FOR $3;
   v_branch ALIAS FOR $4;
BEGIN
RETURN 0;
END getprice;

'  LANGUAGE 'plpgsql';



Patrick Bye
Programmer / Analyst
Westfair Foods Ltd.
pbye@westfair.ca
(403) 291-6538