Delphi MDI Application and the titlebar of the MDI Children

unit CHILDWIN;
interface
uses Windows, Classes, Graphics, Forms, Controls, StdCtrls;

type
  TMDIChild = class(TForm)
  private
    { Private declarations }
  public
    { Public declarations }
    procedure CreateWindowHandle(const Params: TCreateParams); override;
  end;

implementation

{$R *.dfm}
procedure TMDIChild.CreateWindowHandle(const Params: TCreateParams);
begin
  inherited CreateWindowHandle(Params);
  SetWindowLong(Handle, GWL_EXSTYLE, WS_EX_TOOLWINDOW);
end;
end.

TMyForm = class(TForm)
private
  FCurrentModule : TFrame;
public
  property CurrentModule : TFrame read FModule write SetCurrentModule;
end;

procedure TMyForm.SetCurrentModule(ACurrentModule : TFrame);
begin
  if assigned(FCurrentModule) then
    FreeAndNil(FCurrentModule);  // You could cache this if you wanted
  FCurrentModule := ACurrentModule;
  if assigned(FCurrentModule) then
  begin
    FCurrentModule.Parent := Self;
    FCurrentModule.Align := alClient;
  end;
end;

MyForm.CurrentModule := TSomeFrame.Create(nil);