关于调用Dll窗口的问题,请各位高手帮忙,在线等(50分)

//dll部分
library ProjectDll;
{ Important note about DLL memory management: ShareMem must be the
first unit in your library's USES clause AND your project's (select
Project-View Source) USES clause if your DLL exports any procedures or
functions that pass strings as parameters or function results. This
applies to all strings passed to and from your DLL--even those that
are nested in records and classes. ShareMem is the interface unit to
the BORLNDMM.DLL shared memory manager, which must be deployed along
with your DLL. To avoid using BORLNDMM.DLL, pass string information
using PChar or ShortString parameters. }
uses
Windows,
Messages,
SysUtils,
Classes,
Graphics,
Controls,
Forms,
Dialogs,
UnitDll in 'UnitDll.pas' {Form1};
var
hMutex: hWnd;
procedure ProvaChild(ParentApplication: TApplication;
ParentForm: TForm);
export;
stdcall;
var
Form1: TForm1;
DllProc: Pointer;
{ Called whenever DLL entry point is called }
begin
Application.Initialize;
Application.Title := 'Test';
hMutex := CreateMutex(nil, false, 'Test');
if GetLastError <> Error_Already_Exists then
begin
Application := ParentApplication;
Form1 := TForm1.Create(ParentForm);
Form1.MyParentForm := ParentForm;
Form1.MyParentApplication := ParentApplication;
Form1.Show;
end
else
begin
Application.MessageBox('Dll窗口已经运行！', '提示信息');
ReleaseMutex(hMutex);
end;
end;

procedure DLLUnloadProc(Reason: Integer);
register;
begin
if Reason = DLL_PROCESS_DETACH then
Application := DllApplication;
end;

exports
ProvaChild;
begin
DllApplication := Application;
DLLProc := @DLLUnloadProc;
end.
//主窗口(exe)调用部分
procedure TMainForm.StartClick(Sender: TObject);
var
DllHandle: THandle;
ProcAddr: FarProc;
ProvaChild: T_ProvaChild;
begin

DllHandle := LoadLibrary('ProjectDll');
ProcAddr := GetProcAddress(DllHandle, 'ProvaChild');
if ProcAddr <> nil then
begin
ProvaChild := ProcAddr;
ProvaChild(Application,Self);
end;
end;

dll子窗体关闭的时候我在FromClose里写了
procedure TForm1.FormClose(Sender: TObject;
var Action: TCloseAction);
begin
Action:=caFree;
end;
我调出了dll子窗口一次之后再调的时候就说&quot;Dll窗口已经运行！&quot;是不是我只是把窗体释放掉了没有释放dll资源啊?