Proper case in sql server

CREATE  Function [dbo].[fn_get_ProperCase](@InputString as varchar(8000))
RETURNS VARCHAR(8000)
AS
BEGIN
DECLARE @Index INT
DECLARE @Char CHAR(1)
DECLARE @OutputString VARCHAR(255)

SET @OutputString = LOWER(@InputString)
SET @Index = 2
SET @OutputString = STUFF(@OutputString, 1, 1,UPPER(SUBSTRING(@InputString,1,1)))

WHILE @Index <= LEN(@InputString)
BEGIN
SET @Char = SUBSTRING(@InputString, @Index, 1)

IF @Char IN (' ', ';', ':', '!', '?', ',', '.', '_', '-', '/', '&','''','(')
IF @Index + 1 <= LEN(@InputString)
BEGIN
IF @Char != '''' OR UPPER(SUBSTRING(@InputString, @Index + 1, 1)) != 'S'
SET @OutputString = STUFF(@OutputString, @Index + 1, 1,UPPER(SUBSTRING(@InputString, @Index + 1, 1)))
END
SET @Index = @Index + 1
END

RETURN ISNULL(@OutputString,'')


END