title: Check if div is descendant of another
body: <p><a href="https://stackoverflow.com/questions/1059459/best-way-to-find-out-if-element-is-a-descendant-of-another">Best way to find out if element is a descendant of another</a> there is another question, very similiar to this one but its jquery.</p>
  
  <p>so, how do I do it in js ? 
  I have divs a, b, c, d nested in this order.
  also, not sure if matters, there is another a, b, c... and another. its not just a single element. there is many by same id/class.</p>
  
  <p>so I want to see if d has a parent(no matter how deep it is nested, as long as there is some parent on top its ok) called a.</p>
  
  <p>edit:
  also, I had this idea that I could check childnodes of "a" and see if "d" is one of them, but couldnt implement it. if someone can get it working, itd be awesome.</p>