WriteFile16(const TDesC& aDes)
{
RFs rfs;
rfs.Connect();
RFile fh;
fh.Open(rfs, _L("e://test.txt"), EFileShareAny|EFileStream|EFileRead);
CleanupClosePushL(fh);
TInt offset = 0;
fh.Seek(ESeekEnd, offset);
CleanupStack::PopAndDestroy(&fh);
RFileWriteStream streamfile;
streamfile.Open(rfs, _L("e://test.txt"), EFileWrite);
streamfile.PushL();
streamfile.Sink()->SeekL(MStreamBuf::EWrite, TStreamPos(offset));
streamfile.WriteL(aDes);
streamfile.CommitL();
streamfile.Pop();
streamfile.Release();
rfs.Close();
}