how to add preloader to website code example

Example: how to add preloader in html page

$(window).on('load', function() { // makes sure the whole site is loaded 
  $('#status').fadeOut(); // will first fade out the loading animation 
  $('#preloader').delay(350).fadeOut('slow'); // will fade out the white DIV that covers the website. 
  $('body').delay(350).css({'overflow':'visible'});
})