How to find invalid characters in sql server

CREATE  FUNCTION  FindInvalidValid( @Name NVARCHAR(100) )

RETURNS BIT

BEGIN

    SELECT @Name = RTRIM(ltrim(@Name))

    IF(@name IS null) OR (@Name = '')

      RETURN 1



    DECLARE @len AS INT

    DECLARE @index AS INT

    DECLARE @ascii AS int

    SELECT @len =  LEN(@Name),@index = 1

    WHILE(@index <= @len)

    BEGIN

      SELECT @ascii = ASCII(substring(@Name,@index,1))

      IF ((@ascii BETWEEN 65 AND 90)

         OR (@ascii BETWEEN 97 AND 122)

         OR (@ascii BETWEEN 193 AND 252)

         OR (@ascii = 32)

         OR (@ascii = 45)

         OR (@ascii = 46)

         OR (@ascii BETWEEN 48 AND 57)

         )

      begin

         SELECT @index = @index + 1

         CONTINUE

      end

      ELSE

         RETURN 0

    END

    RETURN 1

END

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now use this query for geeting invalid charactor rows

SELECT *

FROM TracedCompanyDetailsttemp

WHERE dbo.IsNameValid(notes1) = 0

OR dbo.IsNameValid(notes1) = 0