小弟有个子窗体显示的问题,向各位大哥大姐请教一下.急!!!!

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, ToolWin, Menus, WinSkinData;type
  TMainForm = class(TForm)
    SkinData1: TSkinData;
    ToolBar1: TToolBar;
    ToolButton2: TToolButton;
    ToolButton1: TToolButton;
    ToolButton3: TToolButton;
    procedure ToolButton1Click(Sender: TObject);
    procedure ToolButton2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  MainForm: TMainForm;implementation{$R *.dfm}
uses Unit2, Unit3;
procedure TMainForm.ToolButton1Click(Sender: TObject);
begin
  lockwindowupdate(handle);
  if not assigned(InputForm) then
    begin
      InputForm:=TInputForm.Create(self);
      InputForm.Width:=MainForm.ClientWidth;
      InputForm.Height:=MainForm.ClientHeight;
      InputForm.Top:=0;
      InputForm.Left:=0;
      if InputForm.WindowState<>wsMaximized then InputForm.WindowState:=wsMaximized;
    end else
      begin
        InputForm.Width:=MainForm.ClientWidth;
        InputForm.Height:=MainForm.ClientHeight;
        InputForm.Top:=0;
        InputForm.Left:=0;
        if InputForm.WindowState<>wsMaximized then InputForm.WindowState:=wsMaximized;
        InputForm.setfocus;
      end;
  lockwindowupdate(0);
end;procedure TMainForm.ToolButton2Click(Sender: TObject);
begin
  lockwindowupdate(handle);
  if not assigned(ViewForm) then
    begin
      ViewForm:=TViewForm.Create(self);
      ViewForm.Width:=MainForm.ClientWidth;
      ViewForm.Height:=MainForm.ClientHeight;
      ViewForm.Top:=0;
      ViewForm.Left:=0;
      if ViewForm.WindowState<>wsMaximized then ViewForm.WindowState:=wsMaximized;
    end else
      begin
        ViewForm.Width:=MainForm.ClientWidth;
        ViewForm.Height:=MainForm.ClientHeight;
        ViewForm.Top:=0;
        ViewForm.Left:=0;
        if ViewForm.WindowState<>wsMaximized then ViewForm.WindowState:=wsMaximized;
        ViewForm.setfocus;
      end;
      lockwindowupdate(0);
end;end.显示子窗体时我是这样写的(介荐别人的),但现在有个问题:
1)、assigned(ViewForm)这个地方,在我关闭子窗体后再打开子窗体时显示就会出错(子窗体我已经cafree了),请问为什么?如何解决？
2）、如果没有关闭的情况我在打开这个子窗体后，这个子窗体的标题按钮丢失，一定要再双击该子窗体的标题头才恢复。如何解决？
3）、我想把这个子窗体内容显示在panel中，也就是parent为panel不过在上述语句中无法显示子窗体，BringToFront也没有反应，请问如何解决？三个问题在线等待，解决后立即给分。谢了各位。