急，关于word的saveas方法的调用，另存为的WORD文件是空白的，为什么呢

Question

代码如下
Document d = (Document)oDocument;
            d.Save();            object FileName = "c:\\myfile.doc";            object FileFormat = Word.WdSaveFormat.wdFormatText;
            object LockComments = false;
            object AddToRecentFiles = true;
            object ReadOnlyRecommended = false;
            object EmbedTrueTypeFonts = false;
            object SaveNativePictureFormat = true;
            object SaveFormsData = true;
            object SaveAsAOCELetter = false;
            object Encoding = MsoEncoding.msoEncodingUSASCII;
            object InsertLineBreaks = false;
            object AllowSubstitutions = false;
            object LineEnding = Word.WdLineEndingType.wdCRLF;
            object AddBiDiMarks = false;            Object missing = Missing.Value;
            d.SaveAs(ref FileName, ref FileFormat, ref LockComments,
            ref missing, ref AddToRecentFiles, ref missing,
            ref ReadOnlyRecommended, ref EmbedTrueTypeFonts,
            ref SaveNativePictureFormat, ref SaveFormsData,
            ref SaveAsAOCELetter, ref Encoding, ref InsertLineBreaks,
            ref AllowSubstitutions, ref LineEnding, ref AddBiDiMarks);
            d.Save();
            MessageBox.Show("保存成功");
            d = null;