C# program small application create in netbean

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 groupbox         {         publicpartialclassForm1:Form         { public Form1()         {         InitializeComponent();         }         privatevoid checkBox5_CheckedChanged(object sender,         EventArgs e)         {         if(checkBox5.Checked)         {         groupBox1.Visible=true;         button1.Visible=true;         checkedListBox1.Visible=true;         button2.Visible=true;         }         else         {         groupBox1.Visible=false;         button1.Visible=false;         checkedListBox1.Visible=false;         button2.Visible=false;         }         }         privatevoid button1_Click(object sender,EventArgs e)         {         String str="";         if(checkBox1.Checked)         {         str+=checkBox1.Text+"\n";         }         if(checkBox2.Checked)         {         str+=checkBox2.Text+"\n";         }         if(checkBox3.Checked)         {         str+=checkBox3.Text+"\n";         }         if(checkBox4.Checked)         {         str+=checkBox4.Text+"\n";         }         MessageBox.Show(str);         }         privatevoid button2_Click(object sender,EventArgs e)         {         String str="";         CheckedListBox.CheckedItemCollection con=checkedListBox1.CheckedItems;         for(int i=0;i<con.Count;i++)         {         str+=con[i].ToString()+",";         }         if(str!="")         {         str=str.Substring(0,str.Length-1);         MessageBox.Show(str);         }         }         }         }