Back to TOP

back_to_top.css

/* scroll to top buttton */
a.scrollToTop{
    width:75px; 
    height:75px;
    text-align:center; 
    background: whiteSmoke;
    text-decoration: none;
    position:fixed;
    bottom:30px;
    right:30px;
    display:none;
    background: url('../images/scroll_to_top.png') no-repeat;
    z-index: 100;
}
a:hover.scrollToTop{
    text-decoration:none;
    cursor: pointer;
}

back_to_top.html

<div id="scroll-to-top"><a href="#top" class="scrollToTop" title='вверх'></a></div>

back_to_top.js

$(document).ready(function(){
    
    //Check to see if the window is top if not then display button
    $(window).scroll(function(){
        if ($(this).scrollTop() > 300) {
            $('.scrollToTop').fadeIn();
        } else {
            $('.scrollToTop').fadeOut();
        }
    });
    
    //Click event to scroll to top
    $('.scrollToTop').click(function(){
        $('html, body').animate({scrollTop : 0},800);
        return false;
    });
});