title: How to select all checkboxes with class "xxx"?
body: <p>Welcome,</p>
  
  <p>It it possible to select all checkboxes / uncheck all checkboxes what have class "xxx" ?</p>
  
  <p>I can't  use "name" and "ID" because there are generated dynamical via PHP and i don't know their name.</p>
  
  <p>So maybye i can add class "xxx" for these what i wan't control ?</p>
  
  <p>Is is possible ?</p>
  
  <p>Or, if not possible.
  Maybye i can select all / unselect  what are inside table with id "selectall" ?</p>
  
  <p>Regards</p>