$('body').prepend('<a id="back-to-top">↑</a>');
$('#back-to-top').addClass(position);
if ($('#back-to-top').length) {
    scrollTrigger,
        backToTop = function () {
            var scrollTop = $(window).scrollTop();
            if (scrollTop > scrollTrigger) {
                $('#back-to-top').fadeIn();
            } else {
                $('#back-to-top').fadeOut();
            }
        };
    backToTop();
    $(window).on('scroll', function () {
        backToTop();
    });
    $('#back-to-top').on('click', function (e) {
        e.preventDefault();
        $('html,body').animate({
            scrollTop: 0
        }, 700);
    });
}

if(imgUrl != '')
  $('#back-to-top').text("").css('background', 'url(' + imgUrl + ') no-repeat center').css("background-size", "contain").css("border","0");

if(topText != '')
  $('#back-to-top').text(topText).css("border","0").css("background-color","transparent");