F4 functionality not available for a Search help field

Question

Dear All,
I have created one search help ZMVGR1 containing :
1) MATNR
2) VKORG
3) VTWEG
4) MVGR1
Selection Method: MVKE
Dialog type: Display value with restriction.
Field               iMPORT   EXPORT    LPOS   SPOS  
MATNR                               X             4                 
VKORG              X              X             1            1
VTWEG              X              X             2            2
MVGR1              X              X             3            3
First I will put VKORG, VTWEG and MVGR1 on screen and then fetch all the fields based on the selection criteria. The problem is on the screen, F4 help for MVGR1 is not coming, for VKORG and VTWEG it is showing. Also while testing in SE11, after filling i parameters when I am pressing F4 help  on any other field., F4 on MVGR1 is coming but F4 on field for which I pressed does not come. At a time out of 3 only two F4 comes. Can anybody tell me how to resolve it. Is it a standard SAP functionality or is there any way to bypass it. I need F4 for all the fields in import parameters, so that all the values gets displayed in export parameters in list. Also note that dialog type is display value with restriction , not display value immediately.
Regards
Debopriyo

Answer 1

Solved. I added one search help exit and inserted the following code after that F4 for all the field are coming in the dialog screen.
field-symbols: <shlp1> type SHLP_DESCR,
               <shlp2> type ddshiface.
IF CALLCONTROL-STEP = 'PRESEL'.
ASSIGN SHLP TO <SHLP1>  .
  READ TABLE <SHLP1>-INTERFACE assigning <shlp2> with key f4field = 'X'.
  IF sy-subrc = 0.
    <shlp2>-f4field = ' '.
  endif.
ENDIF.
Regards
Debopriyo