Incorrect Syntax Near The Keyword 'RETURN'

Hi ,
Can you tell me what is wrong with the following function. I'm getting an Incorrect syntax near the keyword 'RETURN'
FYI. I'm new in this and I'm starting to write functions in SQL server 2005.

ALTER FUNCTION [dbo].[f_sty_print_menu_per_role_per_app2]
(
-- Add the parameters for the function here
@menu_name VARCHAR(255) = NULL ,
@is_user VARCHAR(255) = NULL ,
@is_appl VARCHAR(255) = NULL
)
RETURNS VARCHAR
AS
BEGIN
-- Declare the return variable here
DECLARE @Rows NUMERIC(10)
DECLARE @RETURN_ENABLED VARCHAR(1)

-- Add the T-SQL statements to compute the return value here
SELECT @Rows = MAX(PROFILE_INDEX) FROM PROFILE_PERMISSION PP
INNER JOIN sys_menu_item ON PP.MENU_ITEM=sys_menu_item.menu_item
WHERE PP.PROFILE_INDEX in (select up.profile_index from user_profile up where up.user_id= @is_user) and
not exists (select up.profile_index from user_profile up where up.user_id= @is_user and up.profile_index=1) and
PP.APPLICATION_CODE = @is_appl AND
PP.MENU_NAME=@menu_name
Group By Profile_INdex

Exec (@Rows);

IF @Rows > 0
SELECT @RETURN_ENABLED = 'N'
ELSE
SELECT @RETURN_ENABLED = 'Y';
END

-- Return the result of the function
RETURN @RETURN_ENABLED;

END

Thank you