public DocumentFile AddFile(String id, String fn) { DocumentFile doc = new DocumentFile(id); foreach (DocumentFile d in m_FileList) { if (d.ItemID == doc.ItemID) throw new MobiEPUBexception("Duplicate document itemid '" + doc.ItemID + "' used for files '" + fn + "' and '" + d.Filename); } doc.Filename = fn; m_FileList.Add(doc); return doc; }