Practica extra problema 3 visual

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 examen_2__Windows

{

public partial class Form1 : Form

{

double lim, peso, sum;

public Form1()

{

InitializeComponent();

sum = 0;

}

private void button1_Click(object sender, EventArgs e)

{

lim = double.Parse(textBox1.Text);

listBox1.Items.Add("\tPESO INDIVIDUAL");

textBox1.Enabled = false;

button1.Enabled = false;

textBox2.Focus();

}

private void button2_Click(object sender, EventArgs e)

{

peso = double.Parse(textBox2.Text);

if (sum <>

{

sum = sum + peso;

listBox1.Items.Add("\t\t" + peso.ToString());

if (sum > lim)

{

listBox1.Items.Add("Ha exedido el limite");

listBox1.Items.Add("El peso Total es:" + sum.ToString());

}

if (sum == lim)

{

listBox1.Items.Add("Ha llegado al limite");

listBox1.Items.Add("El peso Total es:" + sum.ToString());

}

textBox2.Clear();

textBox2.Focus();

}

else

{

textBox2.Enabled = false;

button2.Enabled = false;

}

}

private void button3_Click(object sender, EventArgs e)

{

Close();

}

private void button4_Click(object sender, EventArgs e)

{

listBox1.Items.Clear();

}

}

}