main.dfm

How to implement Windows CallBack with using delphi

object MainForm: TMainForm
  Left = 416
  Top = 159
  Width = 217
  Height = 310
  Caption = 'CallBack'
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object Label1: TLabel
    Left = 32
    Top = 232
    Width = 31
    Height = 13
    Caption = 'Label1'
  end
  object Button1: TButton
    Left = 8
    Top = 8
    Width = 173
    Height = 25
    Caption = 'Enumerate Windows'
    TabOrder = 0
  end
  object Memo1: TMemo
    Left = 4
    Top = 44
    Width = 185
    Height = 133
    Lines.Strings = (
      'Memo1')
    ScrollBars = ssBoth
    TabOrder = 1
  end
  object Button2: TButton
    Left = 56
    Top = 232
    Width = 75
    Height = 25
    Caption = 'Button2'
    TabOrder = 2
    OnClick = Button2Click
  end
  object Edit1: TEdit
    Left = 24
    Top = 192
    Width = 121
    Height = 21
    TabOrder = 3
    Text = 'Edit1'
  end
  object Button3: TButton
    Left = 128
    Top = 192
    Width = 75
    Height = 25
    Caption = 'Button3'
    TabOrder = 4
    OnClick = Button3Click
  end
end