/// <summary>
        /// method for editing the article
        /// </summary>
        private void SaveExecute()
        {
            try
            {
                using (WarehouseEntities1 context = new WarehouseEntities1())
                {
                    int id = article.ArticleID;

                    // finding the article with the ID
                    tblArticle newArticle = (from x in context.tblArticles where x.ArticleID == id select x).First();

                    if (article.Article.All(Char.IsLetter))
                    {
                        newArticle.Article = article.Article;
                    }
                    else
                    {
                        MessageBox.Show("Wrong article name input, please try again.");
                    }

                    newArticle.Code      = article.Code;
                    newArticle.Amount    = article.Amount;
                    newArticle.Price     = article.Price;
                    newArticle.Stored    = false;
                    newArticle.ArticleID = article.ArticleID;


                    context.SaveChanges();

                    IsUpdateArticle = true;
                }
                editArticle.Close();
            }
            catch (Exception)
            {
                MessageBox.Show("Wrong inputs, please try again.");
            }
        }