to stop repeating

Hi Vikram,

do like this

data: wa1 like line of wa,
        lv_lines type i,
        cnt type i.
descibe table itab lines lv_lines.
loop at itab into wa.
 cnt = cnt + 1.
 if wa-doc = wa1-doc.
  delete itab from wa.
  modify itab from wa.
 endif.
 if cnt = lv_lines.
  xit.
 endif.
wa1 = wa.
endloop.

Regards,

Satish

Create a table, copy of your itab, and then:

LOOP AT itab1.
  ON CHANGE OF itab1-doc.
* // This restart the cycle
     l_counter = 0.
  ENDON.
  l_counter = l_counter + 1.
  CONCATENATE 'TAX' l_counter INTO l_field.
  ASSIGN COMPONENT l_field OF STRUCTURE itab1 TO <field1>.
  IF sy-subrc NE 0.
* // Lines of DOC finished or components finished.
    APPEND wa TO itab2.
    CONTINUE.    
  ENDIF.
  ASSIGN COMPONENT l_field OF STRUCTURE wa    TO <field2>.
  IF sy-subrc NE 0.
    APPEND wa TO itab2.
    CONTINUE.
  ENDIF.
  IF <field1> IS NOT INITIAL.
    <field2> = <field1>.
  ENDIF.
ENDLOOP.

Hope this helps.

R.