text: /* Set the width of the side navigation to 250px */
  //source: w3schools
  function openNav() {
      document.getElementById("mySidenav").style.width = "250px";
    }
    
    /* Set the width of the side navigation to 0 */
    function closeNav() {
      document.getElementById("mySidenav").style.width = "0";
    }