title: Detect if a mouse event occurred inside an element's client area
body: <p>What is the proper way in Javascript to detect if a mouse event has occurred inside or outside an element's client area?</p>
  
  <p>I have a container with a border and a scrollbar that serves as a control group. I would like to programmatically focus the active element in the group when the user clicks anywhere inside the container's client area but not when they click on the scollbar.</p>