add a class by jquery code example
Example 1: jquery add class
$('some_element').addClass('some-class');
// You can add more than one class at one time
$('some_element').addClass('some-class another-class yet-another-class');
// Even thought jQuery allows you to do this
$('some_element').addClass('some-class').addClass('another-class').addClass('yet-another-class');
// That would be really wasteful, think of the planet!
// But more importantly, your RAM
// oh and those poor folks who be viewing your website
Example 2: add class jquery
$("#my_id").attr("class", "my_new_class_name");
Example 3: jquery add class to body
$('body').addClass(newClass);