ByteAnd()

         Makes an And of two bytes bit to bit

    Syntax:

         ByteAnd ( cByte1, cByte2 ) -> cNewByte

         cByte1 y cByte2 : Bytes to do the And.

    Description:

         Makes an And Between the two specified bytes and returns the
         new byte as the result.

    Return:

         The resulting byte of the And or Nil if any of the two entry bytes
         are not character type.

    Example:

         ? ByteAnd ( "O", "A" )