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var 
    FDevice: PChar;
    FDriver: PChar;
    FPort: PChar;
    DeviceMode: THandle;
    DevMode: PDeviceMode;
begin
  Printer.GetPrinter(FDevice, FDriver, FPort, DeviceMode);
  DevMode := GlobalLock(DeviceMode);

  DevMode^.dmFields := DevMode^.dmFields or DM_PRINTQUALITY;

  case pQuality of
      Low: DevMode^.dmPrintQuality := DMRES_LOW;
      Med: DevMode^.dmPrintQuality := DMRES_MEDIUM;
      High: DevMode^.dmPrintQuality := DMRES_HIGH;
  else
      DevMode^.dmPrintQuality := DMRES_DRAFT;
  end;

  Printer.SetPrinter(FDevice, FDriver, FPort, DeviceMode);
  GlobalUnlock(DeviceMode);
end;