public void SubmitProposal(string paper_name, string co_authors, string[] keywords,
                            string[] topics, string path_to_abstract, string path_to_paper, Edition current, User author)
 {
     if (path_to_abstract != null && !(path_to_abstract.Equals("")))
     {
         ValidationData.ValidatePdfFile(path_to_abstract);
         PostPaperToServerTemp(path_to_abstract, current, author, "Abstract");
     }
     if (path_to_paper != null && !(path_to_paper.Equals("")))
     {
         ValidationData.ValidatePdfFile(path_to_paper);
         PostPaperToServerTemp(path_to_paper, current, author, "Paper");
     }
     ValidationData.ValidateDeadline(current);
     server.AddProposal(
         paper_name,
         co_authors,
         keywords,
         topics,
         path_to_abstract,
         path_to_paper,
         author,
         current
         );
 }