Velocity.js jQuery smooth scroll to #id

scroll2.js

/* Scroll2
=======================

Takes one argument, `speed`. Defaults to 500.

Examples:

$('.scroll2').scroll2(); // <a href="#contact" class="scroll2">Contact me</a>

$('#scrollToTop').scroll2(700); // <a href="#header" id="scrollToTop">Scroll to top</a>

*/
$.fn.scroll2 = function (speed) {
  var destination = $(this).attr('href');

  $(this).on('click', function(e){
    e.preventDefault();
    $(destination).velocity('scroll',{
      duration: speed || 500,
      easing: 'ease-in-out-sine'
    });
  })
}