Decrease slider height

Using this snippet you can decrease the default slider’s height

jQuery(function($) {
   function headerDecrease() {
      var slideHeight = $('#slideshow').height();
      var newHeight = slideHeight - 150; //Replace 150 with the value you want
      $('#slideshow').height(newHeight);
   }
   $(document).ready(headerDecrease);
   $(window).on('resize',headerDecrease);
});

Tip: replace 150 with the value you want.