public ActionResult VariableStructure(VariableSelectionViewModel VariableVM)
        {
            HttpPostedFileBase upload = Request.Files["structure_file"];

            List<string> extensions = new List<string>() { ".txt", ".csv" };
            string extension = Path.GetExtension(upload.FileName);
            if (!extensions.Contains(extension))
            {
                VariableVM.AllVariables = _db.Variables.ToList();
                ViewBag.ErrorMessage = "Improper file type, should be .csv or .txt";
                return View(VariableVM);
            }

            if ((upload.ContentLength <= 0) || (VariableVM.SelectedVariableID == null))
            {
                VariableVM.AllVariables = _db.Variables.ToList();
                return View(VariableVM);
            }

            using (var trans = _db.Database.BeginTransaction(System.Data.IsolationLevel.ReadUncommitted))
            {
                try
                {
                    ParseVariableStructure(VariableVM.SelectedVariableID.Value, upload);
                    trans.Commit();
                }
                catch (Exception Exc)
                {
                    trans.Rollback();
                    ViewBag.ErrorMessage = Exc.Message;
                }
            }

            return RedirectToAction("Index");
        }

        /// <summary>
        /// Go through the uploaded Variable structure file and create the
        /// categories where they do not exist
        /// </summary>
        /// <param name="a_Variable">The Variable to create the structure for</param>
        /// <param name="a_Upload">The uplaoded file with the structure information</param>
        /// σταμάτησα εδώ
        private void ParseVariableStructure(int a_VariableID, HttpPostedFileBase a_Upload)
        {
            string user = User.Identity.Name;
            Variable Variable = _db.Variables.Where(c => c.Id == a_VariableID).FirstOrDefault();

            // Loop through the file entires
            StreamReader sr = new StreamReader(a_Upload.InputStream);
            while (!sr.EndOfStream)
            {
                string line = sr.ReadLine();
                Category parent = null;

                string[] items = line.Split('\t');
                // Level 0 is pre-defined for Family Declaration in order to associate the category
                for (int level = 1; level < items.Length; level++)
                {
                    string curName = items[level];
                    if (string.IsNullOrEmpty(curName))
                        break;

                    // Check if the category of our variable already exists
                    VariableClass curVar = Variable.VariableClass.Where(c => c.description == curName).FirstOrDefault();
                    if (curVar != null)
                    {
                        parent = curVar;
                        continue;
                    }
                    else
                    {
                        curVar = new VariableClass();
                        curVar.description = curName;
                        curVar.dateAdded = DateTime.Now;
                        curVar.addedBy = user;
                        curVar.updateBy = user;
                        curVar.dateLastUpdate = DateTime.Now;

                        if (parent != null)
                            curVar.parentId = parent.Id;

                        // Check if a related family is specified
                        if (!string.IsNullOrEmpty(items[0]))
                        {
                            string familyName = items[0].Trim();
                            var family = Variable.VariableFamily.Where(f => f.description == familyName).FirstOrDefault();
                            if (family != null)
                            {
                                curVar.Families = new List<Family>();
                                curVar.Families.Add(family);
                            }
                        }

                        Variable.VariableClass.Add(curVar);
                        parent = curVar;

                    }
                    _db.SaveChanges();
                }
            }

        }

    }
}