Syntax Error in Create Function

Question

This is one of the more confusing functions I've attempted. The logic works within a select statement, but I can't seem to create a user-defined function.

Here's the error:

"You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'delimiter$$ create function checkdate ( p_datetimestamp varchar (6) ) retur' at line 1"

Here's the code: (Changing a text string 'yymmdd' into date format. '100810' becomes 2010-09-01 per the logic.)

delimiter$$
create function `checkdate` (
 p_datetimestamp varchar (6)
 )
 returns date

begin
declare ret_val date;
set ret_val = 
   str_to_date(
 concat(
  /*Assign Year -> %y*/
    if(
    mid(p_datetimestamp,3,2) = '12',
    (left(p_datetimestamp,2) + 1),
    left(p_datetimestamp,2)
    ),
  /*Assign Month -> %m*/
    if(
    (mid(p_datetimestamp,3,2) >= '01' and mid(p_datetimestamp,3,2) <= '11'),
    concat('0', (mid(p_datetimestamp,3,2) + 1)), '01'
    ),
  /*Assign Date -> %d*/
    if(
    (mid(p_datetimestamp,5,2) >= '01' and mid(p_datetimestamp,5,2) <= '16'), '01', '17'
    ),
 ), 
    '%y%m%d');
return ret_val;
end$$

Answer 1

A rogue comma right at the end

DELIMITER $$

create function `checkdate` (
 p_datetimestamp varchar (6)
 )
 returns date

begin
declare ret_val date;
set ret_val = 
   str_to_date(
 concat(
  /*Assign Year -> %y*/
    if(
    mid(p_datetimestamp,3,2) = '12',
    (left(p_datetimestamp,2) + 1),
    left(p_datetimestamp,2)
    ),
  /*Assign Month -> %m*/
    if(
    (mid(p_datetimestamp,3,2) >= '01' and mid(p_datetimestamp,3,2) <= '11'),
    concat('0', (mid(p_datetimestamp,3,2) + 1)), '01'
    ),
  /*Assign Date -> %d*/
    if(
    (mid(p_datetimestamp,5,2) >= '01' and mid(p_datetimestamp,5,2) <= '16'), '01', '17'
    ) /*<-- Comma Removed from Here*/
 ), 
    '%y%m%d');
return ret_val;
end$$