Right$ (string, length)

   Synopsis:
      Returns a string within a string, starting from the end

   Notes:
      If length is 0, an empty string is returned. If length is greater than the
         length of string, the whole string is returned. If length is a negative
         number, an error is generated.
         
   Examples:
      ! Return the last 4 characters in the string
      Right$ ("Read my lips", 4)
