function resizeNavbar(event) {
    var pageX = event.pageX,
      pageXPlusPx = event.pageX + 'px',
      min = Number.parseInt(NAVBAR_OPTIONS.min, 10) || 300,
      max = Number.parseInt(NAVBAR_OPTIONS.max, 10) || 600;

    /**
         * Just to add some checks. If min is smaller than 10 then
         * user may accidentally end up reducing the size of navbar
         * less than 10. In that case user will not able to resize navbar
         * because navbar slider will be hidden.
         */
    if (min < 10) {
      min = 10;
    }

    /**
         * Only resize if pageX in range between min and max
         * allowed value.
         */
    if (min < pageX && pageX < max) {
      navbar.style.width = pageXPlusPx;
      mainSection.style.marginLeft = pageXPlusPx;
      footer.style.marginLeft = pageXPlusPx;
    }
  }
Check whether we have any resize value in local storage or not.
If we have resize value then resize the navbar.