(function($) { 
    // When to show the scroll link
    // higher number = scroll link appears further down the page   
    var upperLimit = 1000;
    
    // Our scroll link element
    var scrollElem = $('#totop');
   
    // Scroll to top speed
    var scrollSpeed = 500;
   
    // Show and hide the scroll to top link based on scroll position   
    scrollElem.hide();
    $(window).scroll(function () {            
        var scrollTop = $(document).scrollTop();       
        if ( scrollTop > upperLimit ) {
            $(scrollElem).stop().fadeTo(300, 1); // fade back in           
        }else{       
            $(scrollElem).stop().fadeTo(300, 0); // fade out
        }
    });
    // Scroll to top animation on click
    $(scrollElem).click(function(){
        $('html, body').animate({scrollTop:0}, scrollSpeed); return false;
    });
})(jQuery);
(function($) { 
    // When to show the scroll link
    // higher number = scroll link appears further down the page   
    var upperLimit = 100;
    
    // Our scroll link element
    var scrollElem = $('#totop');
   
    // Scroll to top speed
    var scrollSpeed = 500;
   
    // Show and hide the scroll to top link based on scroll position   
    scrollElem.hide();
    $(window).scroll(function () {            
        var scrollTop = $(document).scrollTop();       
        if ( scrollTop > upperLimit ) {
            $(scrollElem).stop().fadeTo(300, 1); // fade back in           
        }else{       
            $(scrollElem).stop().fadeTo(300, 0); // fade out
        }
    });
    // Scroll to top animation on click
    $(scrollElem).click(function(){
        $('html, body').animate({scrollTop:0}, scrollSpeed); return false;
    });
})(jQuery);
modify totop button show scroll limit from 1000 to 100.