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

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected double add(double a, double b)
    {
        double tulos = a + b;
        return tulos;
    }

    protected double sub(double a, double b)
    {
        double tulos = a - b;
        return tulos;
    }

    protected double mul(double a, double b)
    {
        double tulos = a * b;
        return tulos;
    }

    protected double div(double a, double b)
    {
        double tulos = a / b;
        return tulos;
    }

    protected void ButtonTulos_Click(object sender, EventArgs e)
    {
        double luku1, luku2;
        double.TryParse(TextBoxEka.Text, out luku1);
        double.TryParse(TextBoxToka.Text, out luku2);
        //TextBoxTulos.Text += "\n"+add(luku1, luku2);
        if (DropDownListLasku.SelectedIndex == 0)
        {
            //TextBoxTulos.Text += (luku1 + "+" + luku2 + "=" + add(luku1, luku2) + "\n");
            TextBoxTulos.Text = (add(luku1, luku2) + "\n");
        }
        else if (DropDownListLasku.SelectedIndex == 1)
        {
            //TextBoxTulos.Text += (luku1 + "-" + luku2 + "=" + sub(luku1, luku2) + "\n");
            TextBoxTulos.Text = (sub(luku1, luku2) + "\n");
        }
        else if (DropDownListLasku.SelectedIndex == 2)
        {
            TextBoxTulos.Text += (luku1 + "*" + luku2 + "=" + mul(luku1, luku2) + "\n");
        }
        else if (DropDownListLasku.SelectedIndex == 3)
        {
            //TextBoxTulos.Text += (luku1 + "/" + luku2 + "=" + div(luku1, luku2) + "\n");
            TextBoxTulos.Text = (div(luku1, luku2) + "\n");
        }
    }

    protected void TextBox1_TextChanged(object sender, EventArgs e)
    {

    }

    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {

    }
}