protected void AddSeriesButton_Click(object sender, EventArgs e) { NewSeriesTextBox.Visible = true; if (NewSeriesTextBox.Text.Trim() != "") { Serie s1 = new Serie(0, NewSeriesTextBox.Text.Trim()); Series.AddSerie(s1); NewSeriesTextBox.Text = ""; NewSeriesTextBox.Visible = false; SeriesDropDownList.DataSource = Series.GetAllSeries(); SeriesDropDownList.DataTextField = "Series"; SeriesDropDownList.DataValueField = "SeriesID"; SeriesDropDownList.DataBind(); } }