Modify script with Modernizr's touch/no-touch

I have a menu, that follows, when you scroll. It does not work very well on touch devices. Therefor I want the event to only happen on no-touch devices.

I’m using the Responsive theme, which have the Modernizr script. How do I modify my code with touch/no-touch?

This is my script:

$(document).ready(function() {
   $(window).scroll(function() {

       var header = $('#fixed-bar').outerHeight(true);
       console.log(header);
//this will calculate header's full height, with borders, margins, paddings
       var scrollTopVal = $(this).scrollTop();
        if ( scrollTopVal > header ) {
            $('nav').css({'position':'fixed','top' :'0px', 'border-bottom':'4px solid #ff5454'});
        } else {
            $('nav').css({'position':'absolute','top':'90px', 'border-bottom':'none'});
        }
    });
 });