Programa 1 en windows (cuantificador de terreno)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void label2_Click(object sender, EventArgs e)
{
}
private void textBox4_TextChanged(object sender, EventArgs e)
{
}
private void textBox3_TextChanged(object sender, EventArgs e)
{
}
private void button3_Click(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
}
private void button2_Click(object sender, EventArgs e)
{
}
private void calcula_Click(object sender, EventArgs e)
{
double ancho, longitud, costom2;
double costototal;
ancho=double.Parse(txtanchura.Text);
longitud=double.Parse(txtlongitud.Text);
costom2=double.Parse(txtcostom2.Text);
costototal=ancho*longitud*costom2;
txtcostototal.Text=costototal.ToString();
//08211334*RAMIREZ ARZATE FORTUNATO*//
}
private void limpia_Click(object sender, EventArgs e)
{
txtanchura.Clear();
txtlongitud.Clear();
txtcostom2.Clear();
txtcostototal.Clear();
txtanchura.Focus();
}
private void salir_Click(object sender, EventArgs e)
{
Close();
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
private void textBox2_TextChanged(object sender, EventArgs e)
{
}
private void txtlongitud_TextChanged(object sender, EventArgs e)
{
}
}
}