Problem with hiding text-symbols

Hi Experts,

I have one selection screen having a check box and text symbol.

SELECTION-SCREEN:PUSHBUTTON 1(10) pu_attr USER-COMMAND push1.
PARAMETERS ch_docu AS CHECKBOX MODIF ID FST. 
SELECTION-SCREEN COMMENT 3(34) text-c01 MODIF ID FST.

AT SELECTION-SCREEN.

  IF sy-ucomm = 'PUSH1'.
    LOOP AT SCREEN.
      IF SCREEN-group1 = 'FST'.
         SCREEN-INVISIBLE = 1.
        MODIFY SCREEN.
      ENDIF.
    ENDLOOP.
   ENDIF.

.

If user clicks on the push button Checkbox will be made invisible.The check box is invisble But my problem is i am not able to hide the text symbol text-c01. Its still appears on the selection-screen.Not sure where i am going wrong.I tried setting screen-active = 0 .But still not working.

Can anyone please help me?

Regards,

lakshman.