title: Hide or show a picturebox when mouse moves over another
body: <p>My goal is to create this scenario: </p>
  
  <ul>
  <li>if the mouse goes over picturebox1, then picturebox2 will show.</li>
  <li>if not over picturebox1, then picturebox2 won't show</li>
  </ul>
  
  <p>How can I write C# code to perform this?</p>