DATA LAST_DATE TYPE SY-DATUM.

CALL FUNCTION 'LAST_DAY_OF_MONTHS'

  EXPORTING

    day_in            = sy-datum

  IMPORTING

    last_day_of_month = last_date

  EXCEPTIONS

    day_in_no_date    =

    OTHERS            = .

DATA tax_rate_char() TYPE c.

DATA tax_rate TYPE I.

tax_rate_char = '  16%'.

CALL FUNCTION 'PREPARE_STRING'

  EXPORTING

    i_valid_chars  = '  0123456789.'

    i_xvalid_check = 'X'

    i_xchar_repl   = 'X'

    i_xtoupper     = 'X'

  CHANGING

    c_string       = tax_rate_char.

tax_rate = tax_rate_char.