void usb_dwnload(int len)
{
  ret = DeviceIoControl (hf,                         // hDevice: THandle
                         IOCTL_Ezusb_ANCHOR_DOWNLOAD,// dwIoControlCode: DWORD
                         &mass_data,                      // lpInBuffer: Pointer
                         len,                        // nInBufferSize: DWORD
                         NULL,                        // lpOutBuffer: Pointer
                         0,                          // nOutBufferSize: DWORD
                         &nbyte,                      // var lpBytesReturned: DWORD
                         NULL);                        // lpOverlapped: POverlapped
   if (ret==false)
    {
     ShowMessage("LoadError");
    }
 }