C# 라디오 버튼 값 받기

namespace WindowsApplication11
{
 public partial class Form1 : Form
 {
  public Form1()
  {
   InitializeComponent();
  }

  private void checkBox1_CheckedChanged(object sender, EventArgs e)
  {
   MessageBox.Show(Convert.ToString(sender));

   if (((CheckBox)sender).Checked)
    button1.Enabled = false;
   else
    button1.Enabled = true;
  }

  private void checkBox2_CheckedChanged(object sender, EventArgs e)
  {
   MessageBox.Show(Convert.ToString(sender));
   if (((CheckBox)sender).Checked)
    button1.Visible = false;

   else
    button1.Visible=true;
  }
 }
}