c# 4.0 - Interop word application Error in c# -

I need help with this script I am using Word Interop but I get the following error, why?

Thank you.

Error

Set object references to an instance of an object Description: An uncontrolled exception occurred during the execution of existing web requests. For more information about the error, review the stack trace and where it started in the code.

Exception Description: System.NullReferenceException: The object reference is not set to an instance of an object.

  hold (ex before) {oDoc.Close (ref, riff o, referee o); ClientScript.RegisterStartupScript (this.GetType (), "Error Cobie Williams", "Javascript:; Warning ('" + Pre-message +' '') ");}   
  In line   
  oDoc.Close (referee, rif o, referee o);   
  .cs   
  Using the system; Public Partial Class _Default: System.Web.UI.Page {Secure Zero Page_load (Object Sender, EventArgse E) {// Word Application Microsoft is making an example of Office Office.Interop.phord.appption w = newer Object.Office.Internop.wordpress.exe (); Object path = @ "C: \ inetpub \ wwwroot \ WebSite1 \ Kobie_Williams \ id.docx"; Read object = "Redraw"; Object readonly = False; Object o = System. Reflection.Missing.Value; // Opening document Microsoft.Office.Interop.Word.Documentary oDoc = w.Documents.Open (Ref: referee, reef readon, riff o, riff o, riff o, riff o, riff o , For each paragraph in the document foreach (oDoc.Paragraphs in Microsoft.Office.Interop.Word.Paragraph p), the Riff O, Rif O, Ref, Riff O, Ref O, Riff O, Ref O, Ref. / Lu Try {Microsoft.Office.Interop.Word.Range rng = p.Range; Microsoft.Office.Interop.Word.Style styl = rng.get_Style () as Microsoft.Office.Interop.Word.Style; // Check if the document containg table if ((bool) rng.get_Information (Microsoft.Office.Interop.Word.WdInformation.wdWithInTable) == true) {// In the table foreach loop for each cell (Microsoft.Office.Interop. Word (CRGCNS Seals) {if (rng.Cells.Count> 0) {// Checking the desired area in the table (c.ange.text.ToString (). It contains ("Id") edit // edit values ​​in tables c.Next.Range.Text = "1"; if (C. range.txt.ToString () is included ("name")) c.Next .Range.Text = "Haider"; if (C. range text. Toaster (). ("Address")) c.Next.Range.Text = "cabbie-Williams";}} // saving document oDoc.Save ();}} // closing document oDoc.Close (ref, riff o, Referee o);} hold (ex before) {oDoc.Close (referee, riff o, referee o); ClientScript.RegisterStartupScript (this.GetType (), "Error Cobie Williams", "Javascript:; Warning ('" Message + '' ') ");}}    
 
 
 This is probably ODOK zero Because the file has failed to load on  w.Documents.Open () .   
 In addition, it should only be done at one time  
  if (odok! = Null) oDoc.Close ()   blocks  blocks  and  hold  are not repeated in the block.  
 In addition, using Office Interop is usually a bad idea on the web server: