// Import BlockInput function form user32.dll:
// BlockInput Funktion von user32.dll importieren:
function BlockInput(fBlockInput: Boolean): DWORD; stdcall; external 'user32.DLL';
{block input/ blockieren}
procedure TForm1.Button1Click(Sender: TObject);
begin
BlockInput(True);
end;
{Unblock input / Blockierung aufheben}
procedure TForm1.Button2Click(Sender: TObject);
begin
BlockInput(False);
end;orm