C# MS Word Mail Merge

...public void WORDOLUSTUR()
        {
            var application = new Microsoft.Office.Interop.Word.Application();
            var document = new Microsoft.Office.Interop.Word.Document();

            document = application.Documents.Add(Template: @"C:\DOC.docx");
            application.Visible = true;

            foreach (Microsoft.Office.Interop.Word.Field field in document.Fields)
            {
                if (field.Code.Text.Contains("MARKA"))
                {
                    field.Select();
                    application.Selection.TypeText(snltbl.Rows[SIRA][1].ToString());
                    //application.Selection.Text.Replace("MERGEFIELD MARKA", snltbl.Rows[SIRA][1].ToString());
                   
                }
                else if (field.Code.Text.Contains("MODEL"))
                {
                    field.Select();
                    application.Selection.TypeText(snltbl.Rows[SIRA][2].ToString());
                } 
            }

            document.SaveAs2(FileName: @"C:\DOC2.docx");
            document.Close();
            application.Quit();
            Process.Start("WINWORD.EXE", @"C:\DOC2.docx");

        }