Change Element Background During Scroll

JavaScript
7

I needed to put the site back to its original state. I’ve also tried, again, this code:

  <script>
jQuery(window).scroll(function() {    
    var scroll = $(window).scrollTop();

    if (scroll >= 150) {
        $("header").addClass("white");
    } else {
        $("header").removeClass("white");
    }
}); 

</script>

and it didn’t work. So, obviously, there’s a conflict somewhere.