using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.Configuration; namespace ConfigurationC { public partial class Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { TextBox1.Text = WebConfigurationManager.AppSettings["MailServer"]; } } } }