protected void showSelectedNumBooksButton_Click(object sender, EventArgs e) { List <Book> books = new List <Book>(); aBook = new Book(); aBookBll = new BookBLL(); borrowedBookListDropDownList.DataTextField = "Title"; string number = memberNumberTextBox0.Text; books = aBookBll.GetAllBooksByNumber(number); borrowedBookListDropDownList.Items.Clear(); foreach (var book1 in books) { borrowedBookListDropDownList.Items.Add(book1.Title); } }