Question : delphi Run once

I have many delphi forms in my project...

Where/How am I going to code, if I've declared a run once to my project, THEN, if I run again the program with a parameter, it will show the ParamForm.

// i dont think this is a good idea
{
if Mutex <> 0 then
begin

if paramstr(1)<>'' then
begin
ParamForm.Show;
end

else
CloseHandle(Mutex);
end;
end;
}

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program Project1;

uses
  Forms,
  windows,
  fFwall in 'fFwall.pas' {fMainform},
  uSplash in 'uSplash.pas' {fSplashform},
  fusbscan in 'fusbscan.pas' {usbform},
  dbupdater in 'dbupdater.pas' {dbUpdateForm},
  ParamUnit in 'ParamUnit.pas' {ParamForm};

var
Mutex : THandle;

{$R *.res}

begin
Mutex := CreateMutex(nil, True, 'myapp');
  if (Mutex <> 0) and (GetLastError = 0) then
  begin
   Application.Initialize;

   fSplashForm:=TfSplashForm.Create(Application);
   fSplashForm.Show;

  Application.ShowMainForm := False;
  Application.CreateForm(TfMainform, fMainform);
  Application.CreateForm(Tusbform, usbform);
  Application.CreateForm(TdbUpdateForm, dbUpdateForm);
  Application.CreateForm(TParamForm, ParamForm);
  Application.Run;

    if Mutex <> 0 then CloseHandle(Mutex);
  end;


end.

Answer : delphi Run once

A bit better:

var
LastPos: TPoint = (x:100; y:100);

procedure TMainForm.WndProc(var Message: TMessage);
var
NewParamForm: TParamForm;
begin
if Message.Msg = msg_ShowParamForm then
begin
NewParamForm:= TParamForm.Create(Self);
NewParamForm.Top:= LastPos.x;
NewParamForm.Left:= LastPos.y;
Inc(LastPos.x, 30);
Inc(LastPos.y, 30);
NewParamForm.Show;
end
else
inherited;
end;