PROC EditFieldMain(DeleteBlank)
PRIVATE Ch, Num
  WHILE TRUE
    IF ISBLANK([Index]) THEN
      MESSAGE "Fill in Index field, it can not be blank"
      SLEEP 1000
      MOVETO [Index]
    ENDIF
    WAIT FIELD
    UNTIL 26, -44, ;"Zoom", "ZoomNext"
         -81, -73, -71, -79, ;"PgDn", "PgUp", "Home", "End"
         -77, -75, -72, -80, ; "Right", "Left", "Up", "Down"
         9, -15, 13, ;"Tab", "ReverseTab", "Enter"
         -59, -60, -83, -82, 6, ; "F1", "F2", "Del", "Ins", "FieldView"
         18, 4, -32             ; Ctrl+R, Ctrl+D, Alt+D
    SWITCH
    CASE Retval = 6 :   ;"FieldView"
      KEYPRESS 6
      PromptField()
      WAIT FIELD
      UNTIL 13 ;"Enter"
      PromptEdit()
    CASE DeleteBlank AND Retval = -83 :   ;"Del"
      DEL
      RETURN
    CASE ISBLANK([Index]) :
    OTHERWISE   :
      IF FIELD() = "Index" THEN
        Ch = Retval
        Num = [Index]
        UNLOCKRECORD
        IF RECORDSTATUS("Locked") OR RECORDSTATUS("New") THEN
          MESSAGE "Record with such a number already exists"
          SLEEP 1000
        ELSE
          LOCATE Num
          RETURN Ch
        ENDIF
      ELSE
        RETURN Retval
      ENDIF
    ENDSWITCH
  ENDWHILE
ENDPROC