Send Fax using window 2003

[wnshieng]

I am using FAXCOMEXLib.dll to send fax here. When I send a .txt file to the
fax and it has no problem, but when I send a .html/.pdf/.doc file to fax, it pops up
a logon screen and asking me to login.However, I still cannot fax the file after i have login by using administrator. Can we send a html/pdf/others file types by using FAXCOMEXLib.dll without asking me to login and choose the printer?

Here is by codes and its pretty straight forward.

FaxServer faxServer = new FaxServerClass();
faxServer.Connect(ServerName);
FaxDocument faxDocument = new FaxDocumentClass();
faxDocument.Recipients.Add(FaxNo, "");
faxDocument.Body = FileName;
faxDocument.Priority = FAXCOMEXLib.FAX_PRIORITY_TYPE_ENUM.fptHIGH;
faxDocument.AttachFaxToReceipt = true;
faxDocument.CoverPageType = FAXCOMEXLib.FAX_COVERPAGE_TYPE_ENUM.fcptSERVER;
faxDocument.CoverPage = "generic";
faxDocument.ReceiptType = FAXCOMEXLib.FAX_RECEIPT_TYPE_ENUM.frtMAIL;
faxDocument.Subject = Subject;
faxDocument.ConnectedSubmit(faxServer);
faxServer.Disconnect();

Thank you.