Dropdown lists or F4 (input help) on custom field

Question

I created a custom field and would like to either add a dropdown or an F4 input help.  I know how to do the input help  or the dropdown, but I would like the user to type in their own data on the field if they don't want to select from the list provided.
Does anyone know how to do this.

Answer 1

Check out this code.... This module does F4 help for a screen field called P_TRFAR.   It gets its values from the data base,  you could easily build this internal table in your program without going to the database.
MODULE HELP_ON_TRFAR.
data: begin of help_trfar occurs 0,
       trfar type t510a-trfar,
       tartx type t510a-tartx,
      end of help_trfar.
  select * into corresponding fields of table help_trfar
              from t510a
                    where molga = '10'.
  call function 'F4IF_INT_TABLE_VALUE_REQUEST'
       exporting
            retfield    = 'TRFAR'
            dynprofield = 'P_TRFAR'
            dynpprog    = sy-cprog
            dynpnr      = sy-dynnr
            value_org   = 'S'
       tables
            value_tab   = help_trfar.
ENDMODULE.
In you flow logic, you need the following line to trigger the help when the user presses F4.
PROCESS ON VALUE-REQUEST.
  FIELD P_TRFAR MODULE HELP_TRFAR.
That should be all you need.
Please don't forget to award points accordingly for helpful answers.  Thanks.
Regards,
Rich Heilman
Message was edited by: Rich Heilman