• F4IF_FIELD_VALUE_REQUEST
  主要功能是将表里的字段对应的search help引入到屏幕上来，从而打开对话框，当然也可以任意指定某个search help。
• F4IF_INT_TABLE_VALUE_REQUEST
  支持字定义内表，但是不能通过指定search help的方式打开对话框。

1.F4IF_FIELD_VALUE_REQUEST的应用实例

TYPES: BEGIN OF type_carrid,carrid TYPE spfli-carrid,connid TYPE spfli-connid,carrname TYPE scarr-carrname,END OF type_carrid.DATA itab_carrid TYPE STANDARD TABLE OF type_carrid.PARAMETERS airline(2) TYPE c.
*&---------------------------------------------------------------------*
*& Processing Blocks called by the Runtime Environment                 *
*&---------------------------------------------------------------------*
* Event Block AT SELECTION-SCREEN ON VALUE-REQUEST FOR
AT SELECTION-SCREEN ON VALUE-REQUEST FOR airline.PERFORM frm_f4_help.* Form for generating F4 HELP for parameter AIRLINE
FORM frm_f4_help .SELECT carrid carrnameFROM scarrINTO CORRESPONDING FIELDS OF TABLE itab_carrid.CALL FUNCTION 'F4IF_FIELD_VALUE_REQUEST'EXPORTINGtabname     = 'SPFLI'    "指定stucture，必须的fieldname   = 'CARRID' "指定structure中的fielddynpprog    = sy-repid          "指定屏幕参数所在的程序名称dynpnr      = sy-dynnr          "指定参数所在的屏幕编号dynprofield = 'AIRLINE'.        "指定屏幕参数的名称*  IF sy-subrc <> 0.
*    ...
*  ENDIF.
ENDFORM.                    " FRM_F4_HELP

2.F4IF_INT_TABLE_VALUE_REQUEST的应用实例

TYPES: BEGIN OF type_carrid,carrid TYPE spfli-carrid,connid TYPE spfli-connid,carrname TYPE scarr-carrname,END OF type_carrid.DATA itab_carrid TYPE STANDARD TABLE OF type_carrid.
* Selection Screen
PARAMETERS airline(2) TYPE c.* Event Block AT SELECTION-SCREEN ON VALUE-REQUEST FOR
AT SELECTION-SCREEN ON VALUE-REQUEST FOR airline.PERFORM frm_f4_help.* Form for generating F4 HELP for parameter AIRLINE
FORM frm_f4_help .SELECT carrid carrnameFROM scarrINTO CORRESPONDING FIELDS OF TABLE itab_carrid.CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'EXPORTINGretfield        = 'CARRID'  "指定要返回屏幕参数的在内表中的fieldvalue_org       = 'S'       "S代表structuredynpprog        = sy-repid  "指定屏幕参数所在的程序名称dynpnr          = sy-dynnr  "指定参数所在的屏幕编号dynprofield     = 'AIRLINE' "指定屏幕参数的名称TABLESvalue_tab       = itab_carrid "内表EXCEPTIONSparameter_error = 1no_values_found = 2OTHERS          = 3.
*  IF sy-subrc <> 0.
*    ...
*  ENDIF.
ENDFORM.                    " FRM_F4_HELP

总结：总上所述，在se11已经存在建立好的search help的情况下我们通常使用第一个function module，在需要给某个字段限定一些特殊值的时候，我们通常使用第2种function module.