act 3: string builder

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 button1_Click(object sender, EventArgs e)
{
StringBuilder tok = new StringBuilder(textBox1.Text);
StringBuilder burac = new StringBuilder(textBox2.Text);
if (checkBox1.Checked == true)
{


tok.Append(burac);
label1.Text = tok.ToString();


}
}
}
}