Writting name to the word document

using Microsoft.Office.Core;
using Microsoft.Office;
using Microsoft.Office.Interop.Word;



void InsertInWordDoc(string name)
        {
            try
            {
                string filename = (fpUploadresume.FileName.Substring(fpUploadresume.FileName.LastIndexOf(".") + 1));
                if ((filename == "doc") || (filename == "docx"))
                {
                    if(txtReferredby.Text!="")
                    {
                        object Missing = System.Reflection.Missing.Value;
                        object fileToOpen = (object)PathToSave;
                        Application app = new ApplicationClass();
                        Microsoft.Office.Interop.Word.Document doc = new Microsoft.Office.Interop.Word.Document();
                        doc = app.Documents.Open(ref fileToOpen, ref Missing, ref Missing, ref Missing, ref Missing,
                        ref Missing, ref Missing, ref Missing, ref Missing,
                        ref Missing, ref Missing, ref Missing, ref Missing,
                        ref Missing, ref Missing, ref Missing);
                        Range rg = doc.Range(ref Missing, ref Missing);
                        rg.InsertBefore("Referred by: " + name);
                        rg.Font.Name = "times new roman";
                        rg.Font.Size = 14;
                        rg.InsertParagraphAfter();
                        rg.InsertParagraphBefore();
                        app.Documents.Save(ref Missing, ref Missing);
                        doc.Close(ref Missing, ref Missing, ref Missing);

                    }

                }
            }
            catch (Exception ex)
            {
            }
        }