title: Enabling / Disabling ToolStripMenuItem when clicked
body: <p>I've two forms (called form1 as mdi container and form2) with an opentoolstripmenuitem in form1, when opentoolstripmenuitem clicked form2 called and opentoolstripmenuitem become disable, but when i click closebox in the top right of form2 the opentoolstripmenu still disable, i want it to enable again when closebox clicked.</p>
  
  <p>Here my code in form1 :</p>
  
  <pre><code>private void openToolStripMenuItem_Click(object sender, EventArgs e)
  {
      openToolStripMenuItem.Enabled = false;
      Form2 newMDIChild = new Form2();
      newMDIChild.MdiParent = this;
      newMDIChild.Show();            
  }
  </code></pre>
  
  <p>any advice??</p>