[GENERAL] Script errors on run

[Ralph Smith]

This is my first 'real' script, one that verifies proper format for a  
user-entered date string.
Once that is done I want the script to return the UNIX time.
I plan on invoking this script on a psql connection (via .psqlrc), so  
that I can call it from the command line.

Here's what I have at the end of my script,
************************************

  -- ==========================================
  good_date := to_date(year||'-'||month||'-'||day , 'YYYY-MM-DD') ;

  RAISE NOTICE 'good_date =  %',good_date ;

  Usecs := EXTRACT(EPOCH FROM TIMESTAMP good_date) ;

END ;


Here's what I get when I
*********************

psql -U username dbname  -f myfile.sql
CREATE FUNCTION
psql:myfile.sql:119: ERROR:  syntax error at or near "$1"
LINE 1: SELECT  EXTRACT(EPOCH FROM TIMESTAMP  $1 )
                                              ^
QUERY:  SELECT  EXTRACT(EPOCH FROM TIMESTAMP  $1 )
CONTEXT:  SQL statement in PL/PgSQL function "usecs_from_date" near  
line 92

Is this not a programmable extraction???
I'm missing something here.

Thanks!
Ralph