Hi Yash,
you have commented your function module, as you can see.
and still you think it will work .
** CALL FUNCTION 'SPELL_AMOUNT'
** EXPORTING
** amount = amount
** language = sy-langu
** IMPORTING
** in_words = spell
** EXCEPTIONS
** not_found = 1
** too_large = 2
** OTHERS = 3.
** IF flag = 0.
** CONCATENATE text1 spell-word unit INTO text1 SEPARATED BY ' ' .
** ELSE.
** CONCATENATE text1 'AND' unit spell-word INTO text1 SEPARATED BY
**' '.
** ENDIF.
** CLEAR spell.
**