using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class arvutus3 : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {
     var paarid = File.ReadAllLines(Server.MapPath("~/App_Data/") + "kursid.txt").
      Select(rida => rida.Split(new char[] { ' ' }));
     // ListBox1.Items.Clear();
     if (!IsPostBack)
     {
         foreach (var paar in paarid)
         {
             ListBox1.Items.Add(new ListItem(paar[0], paar[1]));
         }
     }
    }
    protected void arvuta(object sender, EventArgs e) {
        Label1.Text = (double.Parse(ListBox1.SelectedValue) * 
                      double.Parse(TextBox1.Text)).ToString();
    }
}