//显示
if not Assigned(Fm_Pdcl) then begin
Application.CreateForm(TFm_Pdcl, Fm_Pdcl);
end else begin
Fm_Pdcl.Show;
Fm_Pdcl.WindowState:=wsNormal;
Fm_Pdcl.BringToFront;
end;
procedure TFm_Pdcl.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Action:=caFree;
Fm_Pdcl:=nil;
end;