//OBJECT OF MISSING "NULL VALUE"
Object oMissing = System.Reflection.Missing.Value;
//OBJECTS OF FALSE AND TRUE
Object oTrue = true;
Object oFalse = false;
//CREATING OBJECTS OF WORD AND DOCUMENT
Word.Application oWord = new Word.Application();
Word.Document oWordDoc = new Word.Document();
//MAKING THE APPLICATION VISIBLE
oWord.Visible = true;
//ADDING A NEW DOCUMENT TO THE APPLICATION
oWordDoc = oWord.Documents.Add(ref oMissing, ref oMissing, ref oMissing, ref oMissing);
----------------
Object oSaveAsFile = (Object)"C:\\SampleDoc.doc";
oWordDoc.SaveAs(ref oSaveAsFile, ref oMissing, ref oMissing, ref oMissing,
ref oMissing, ref oMissing,ref oMissing, ref oMissing, ref oMissing,
ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing,
ref oMissing, ref oMissing);