title: Send scroll event to form
body: <p>In my windows forms application it occurs frequently that a user scrolls through a panel and is then blocked by a <code>richtextbox</code>. I would like to catch the scroll event and send it to the panel when the <code>richtextbox</code> vertical scrollbar is not visible.</p>
  
  <p>I already found the code to check if the vertical scrollbar is visible in this thread: <a href="https://social.msdn.microsoft.com/Forums/en-US/a3facad3-0eae-4610-9a63-1b6c7a718bf5/how-do-you-determine-if-vertical-scroll-bar-is-visible-in-richtextbox?forum=winforms" rel="nofollow">https://social.msdn.microsoft.com/Forums/en-US/a3facad3-0eae-4610-9a63-1b6c7a718bf5/how-do-you-determine-if-vertical-scroll-bar-is-visible-in-richtextbox?forum=winforms</a></p>
  
  <p>Also the <code>VScroll</code> event of a <code>richtextbox</code> is only triggered when the verticalscrollbar is already visible.</p>
  
  <p>What would be the correct way to catch the mousescroll and send it to the correct panel?</p>