title: How can I detect when a new element has been added to the document in jquery?
body: <p>How can I detect when a new element has been added to the document in jquery ?</p>
  
  <p>Explanation:
  I want to know when an element with class "column-header" has been added to the document. As I plan to run some javascript on those elements.</p>
  
  <p>How can I do this ? I use jQuery javascript library.</p>