private void AddProductFromTextBox()
        {
            // Returns empty string if input is acceptable, and an error message if not.
            string validationResult = ValidateTextInput.ProductName(ProductNameInputTextBox.Text, Products);

            ProductModel newProduct = new ProductModel(ProductNameInputTextBox.Text);

            if (validationResult == "")
            {
                GlobalConfig.Connection.AddProduct(newProduct);

                EditTagsOfProduct editTagsOfProduct = new EditTagsOfProduct(newProduct);
                editTagsOfProduct.ShowDialog();
            }
            else
            {
                MessageBox.Show(validationResult, "Invalid name");
                return;
            }


            ProductNameInputTextBox.Text = "";

            GetDataFromDatabase();
            UpdateListBoxForSelectedTag();
        }
        private void AddTagFromTexBox()
        {
            string validationResult = ValidateTextInput.TagName(TagNameInputTextBox.Text, Tags);

            if (validationResult == "")
            {
                TagModel newTag = new TagModel(TagNameInputTextBox.Text);
                GlobalConfig.Connection.AddTag(newTag);

                EditProductsOfTag editProductsOfTag = new EditProductsOfTag(newTag);
                editProductsOfTag.ShowDialog();
            }
            else
            {
                MessageBox.Show(validationResult, "Invalid name");
            }

            TagNameInputTextBox.Text = "";

            GetDataFromDatabase();
            WireUpTags();
        }