change my upload system with c# -

i want make code upload in .docx or .pdf im confuse, how can change code ? im can upload when data image

there code in aspx.cs

protected void save_click(object sender, eventargs e) {     //upload photo     int h, w; string folder = "photo/";     h = 298; w = 765;     string asl = uploadincresize(h, w, folder, upload, false);     string insert = "insert pm_formkl(title, proponent, assessor, score, upload) "                     + "values('" + cf.strsql(title.text) + "','" + cf.strsql(proponent.text) + "','" + cf.strsql(assessor.text) + "','" + cf.strsql(score.text) + "','" + asl + "')";     db.execute(insert);      response.redirect("/detail penilaian/kl/formkl.aspx"); }  // upload image protected string uploadfile(string folder, fileupload img) {     string upload_file = "";     try     {         string filename = path.getfilename(img.filename);         string dir = param.pathimage + folder;         bool status = true;          while (status)         {             status = fileexists(filename, server.mappath("~/images/" + folder));             if (status)                 filename = getrandomfilename() + system.io.path.getextension(img.postedfile.filename);         }          //teaser_image.saveas(server.mappath("~/images/") + folder + filename);         upload_file = filename;         string large = dir + filename;          img.postedfile.saveas(large);     }     catch (exception ex)     {         js.alert(this, "upload status: file not uploaded. following error occured: " + ex.message);     }     return upload_file; }  protected string uploadincresize(int h, int w, string folder, fileupload img, bool resize) {     string upload_file = "";     try     {         if (img.postedfile.contenttype == "image/jpeg" || img.postedfile.contenttype == "image/png" || img.postedfile.contenttype == "image/gif")         {             string filename = path.getfilename(img.filename);             string dir = param.pathimage + folder;             bool status = true;              while (status)             {                 status = fileexists(filename, server.mappath("~/images/" + folder));                 if (status)                     filename = getrandomfilename() + system.io.path.getextension(img.postedfile.filename);             }              upload_file = filename;              string temp = dir + "(kl)" + filename;             string large = dir + filename;              img.postedfile.saveas(temp);             if (resize)             {                 imgh.crop(temp, large, h, w);             }             else             {                 img.postedfile.saveas(large);             }             file.delete(temp);             js.alert(this, "upload status: upload successfull.");         }         else             js.alert(this, "upload status: jpeg , png or gif files allowed!");     }     catch (exception ex)     {         js.alert(this, "upload status: file not uploaded. following error occured: " + ex.message);     }     return upload_file; }  protected string getrandomfilename() {     random rand = new random((int)datetime.now.ticks);     int newfile = 0;     newfile = rand.next(1, 9999999);      return newfile.tostring(); }  protected bool fileexists(string filename, string path) {     fileinfo imagefile = new fileinfo(path + filename);     bool filestatus = imagefile.exists;     return filestatus; }