Convert Characters

I've created a procedure that converts chracters that I don't want in a certain field in my db.
The problems is: it also converts characters that I haven't specified
For example: the letter y is converted to u (probably because the letter ü (german y) is to be converted to u (ü is pronounced as y)).
Does anyone have a solution for this ? Has soundex something to do with this ?

Regards
Carl Nilsson


Here's a sample of the script:

--script begin

CREATE proc bds_convert_names @pass_name varchar(100), @NameStr varchar(100) OUTPUT
as



DECLARE @NotAllowed varchar(100)
DECLARE @IsAllowed varchar(100)
DECLARE @OldChar char(1)
DECLARE @NewChar char(1)
DECLARE @Loop int

-- NAMESTR = Contains the string that should be translated.
SELECT @NameStr = @pass_name
-- Set the name to Lower Cases
SELECT @NameStr = LOWER(@NameStr)

-- Set the characters not allowed
SELECT @NotAllowed = '/:*?"<>|,åäöéèáàûüôî'
-- Set which characters that should replace them
SELECT @IsAllowed = '**********aaoeeaauuoi'
-- Set Loop start to zero
SELECT @Loop = 0

-- Start looping, char by char, replacing direct into NAMESTR
WHILE @Loop < LEN(@NotAllowed)
BEGIN
SELECT @Loop = @Loop + 1
SELECT @OldChar = SUBSTRING(@NotAllowed, @Loop, 1)
SELECT @NewChar = SUBSTRING(@IsAllowed, @Loop, 1)
SELECT @NameStr = REPLACE(@NameStr, @OldChar, @NewChar)
END


-- Remove all stars
SELECT @NameStr = REPLACE(@NameStr, '*', '')
GO

--script end