c# - Word and Excel files not getting downloaded in my asp.net website -

the below code works if try download .txt/.msg/.pdf/.png/.jpg fails if try download exccel or word files. can please help

        response.contenttype = "application/octet-stream";         //response.contenttype = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";          fileurl = server.urldecode(fileurl);         system.string disheader = "attachment; filename=\"" + fileurl + "\"";         response.appendheader("content-disposition", disheader);         // transfer file byte-by-byte response object          system.io.fileinfo filetodownload = new system.io.fileinfo(fileurl);         response.flush();         response.writefile(filetodownload.fullname);