title: How to close entire application when application has more than 2 forms without showing messagebox more than once
body: <p>I am developing a application using windows forms. The project contains 3 forms: one login form which is the main form and two others which are child forms to the login form.</p>
  
  <p>My problem is when want to close the total application by using <code>Application.Exit()</code> in form closing event my messagebox showing the dialog more than once. </p>
  
  <p>1.This code in Login form i.e main form:</p>
  
  <pre><code>private void FrmLogIn_FormClosing(object sender, FormClosingEventArgs e)
      {
          DialogResult loginResult = MessageBox.Show("Do you want to close this application?","Close",MessageBoxButtons.YesNo,MessageBoxIcon.Warning);
          if (loginResult == DialogResult.Yes)
          {
              Application.Exit();
          }
      }
  </code></pre>
  
  <p>2.AdminForm closing event which is child form to login form:</p>
  
  <pre><code> private void FrmAdmin_FormClosing(object sender, FormClosingEventArgs e)
      {
          DialogResult loginResult = MessageBox.Show("Do you want to close this application?","Close",MessageBoxButtons.YesNo,MessageBoxIcon.Warning);
          if (loginResult == DialogResult.Yes)
          {
              Application.Exit();
          }
      }
  </code></pre>
  
  <p>3.Billoperations form closing event which is child form to login form:</p>
  
  <pre><code>private void FrmBillOperation_FormClosing(object sender, FormClosingEventArgs e)
  {
      DialogResult loginResult = MessageBox.Show("Do you want to close this application?","Close",MessageBoxButtons.YesNo,MessageBoxIcon.Warning);
      if (loginResult == DialogResult.Yes)
      {
          Application.Exit();
      }
  }
  </code></pre>
  
  <p>When i click the close button in any form it will show MessageBox message only once. Please help me.</p>