Convert a text to a Title

How convert a text to a Title text with TSQL. It's "easy" solution.

CREATE FUNCTION udf_TitleCase (@InputString VARCHAR(4000))
RETURNS VARCHAR(4000)
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
GO

SELECT dbo.udf_TitleCase('My test''s tests case of title!')