VBA "本体" 改定

Sub 商品名を入力()


Dim flag As Boolean
Dim i As Integer '行数
Dim j As Integer 'シート数


For j = 1 To Sheets.Count

    If flag = True Then
        flag = False 'フラグのデフォルトはfalse
    End If
    
    Worksheets(j).Activate
    
    For i = 1 To LastRow(ActiveSheet, 1) 'A列の最終行まで。
        
      'フラグ無、かつ、"本体"、でフラグ有へ
      If flag = False Then
        If ActiveSheet.Cells(i, 1).Value = "本体" Then
            flag = True
        End If
      End If
      
      'フラグ有、かつ、セル空白、で"本体"を入れる
      If flag = True Then
        If ActiveSheet.Cells(i, 1).Value = "" Then
            ActiveSheet.Cells(i, 1).Value = "本体"
        End If
      End If
      
      'フラグ有、かつ、空白&"本体"以外、でフラグ無へ（"パーツ"などのときにフラグ無くす）
      If flag = True Then
        If ActiveSheet.Cells(i, 1).Value <> "" Then
            If ActiveSheet.Cells(i, 1).Value <> "本体" Then
               flag = False
            End If
        End If
      End If
    'MsgBox ("rrr")
    Next
Next
End Sub

Function LastRow(sheetobj As Worksheet, C) '戻り値は数値
    LastRow = sheetobj.Cells(sheetobj.Rows.Count, C).End(xlUp).Row
End Function