jQuery.fn.topLink = function(settings) {
     settings = jQuery.extend({
                    min: 1,
                    fadeSpeed: 200,
                    ieOffset: 50
                }, settings);
     return this.each(function() {
         //listen for scroll
         var el = $(this);
         el.css('display','none'); //in case the user forgot
         $(window).scroll(function() {
             if(!jQuery.support.hrefNormalized) {
                 el.css({
                     'position': 'absolute',
                     'top': $(window).scrollTop() + $(window).height() - settings.ieOffset
                 });
             }
             if($(window).scrollTop() >= settings.min)
             {
                 el.fadeIn(settings.fadeSpeed);
             }
             else
             {
                 el.fadeOut(settings.fadeSpeed);
             }
         });
     });
};

$(document).ready(function() {
        $('#gototop').topLink({
                min: 400,
                fadeSpeed: 500
        });
});