how to print word document (2007) in c#

private ApplicationClass wrdApp = null;// new ApplicationClass();
       private Document oDataDoc = null;// new Document();
       //Word.Selection wrdSelection; //word2003
       Selection wrdSelection;//2007

       private void SendToPrinterAcopy(string DocFile)
       {
           Object background = true;
           Object append = false;
           //Object range = Word.WdPrintOutRange.wdPrintAllDocument;
           //Object item = Word.WdPrintOutItem.wdPrintDocumentContent;
           //Object pageType = Word.WdPrintOutPages.wdPrintAllPages;
           Object range = wrdApp.WdPrintOutRange.wdPrintAllDocument;  //<------Error
           Object item = wrdApp.WdPrintOutItem.wdPrintDocumentContent;//<------Error
           Object pageType = wrdApp.WdPrintOutPages.wdPrintAllPages;  //<------Error
           Object copies = 1;//one copy only
           Object printToFile = false;
           //
           oDataDoc.PrintOut(ref background, ref append,
           ref range, ref missing, ref missing, ref missing,
           ref item, ref copies, ref missing, ref pageType,
           ref printToFile, ref missing, ref missing,
           ref missing, ref missing,ref missing, ref missing,
           ref missing);
       }