text: var scrolltotop = { setting: { startline: 100, scrollto: 0, scrollduration: 400, fadeduration: [500, 100] }, controlHTML: '', controlattrs: { offsetx: 30, offsety: 80 }, anchorkeyword: "#top", state: { isvisible: false, shouldvisible: false }, scrollup: function () { if (!this.cssfixedsupport) { this.$control.css({ opacity: 0 }) } var dest = isNaN(this.setting.scrollto) ? this.setting.scrollto : parseInt(this.setting.scrollto); if (typeof dest == "string" && jQuery("#" + dest).length == 1) { dest = jQuery("#" + dest).offset().top } else { dest = 0 } this.$body.animate({ scrollTop: dest }, this.setting.scrollduration) }, keepfixed: function () { var $window = jQuery(window); var controlx = $window.scrollLeft() + $window.width() - this.$control.width() - this.controlattrs.offsetx; var controly = $window.scrollTop() + $window.height() - this.$control.height() - this.controlattrs.offsety; this.$control.css({ left: controlx + "px", top: controly + "px" }) }, togglecontrol: function () { var scrolltop = jQuery(window).scrollTop(); if (!this.cssfixedsupport) { this.keepfixed() } this.state.shouldvisible = (scrolltop >= this.setting.startline) ? true : false; if (this.state.shouldvisible && !this.state.isvisible) { this.$control.stop().animate({ opacity: 1 }, this.setting.fadeduration[0]); this.state.isvisible = true } else { if (this.state.shouldvisible == false && this.state.isvisible) { this.$control.stop().animate({ opacity: 0 }, this.setting.fadeduration[1]); this.state.isvisible = false } } }, init: function () { jQuery(document).ready(function ($) { var mainobj = scrolltotop; var iebrws = document.all; mainobj.cssfixedsupport = !iebrws || iebrws && document.compatMode == "CSS1Compat" && window.XMLHttpRequest; mainobj.$body = (window.opera) ? (document.compatMode == "CSS1Compat" ? $("html") : $("body")) : $("html,body"); mainobj.$control = $('<div id="topcontrol">' + mainobj.controlHTML + "</div>").css({ position: mainobj.cssfixedsupport ? "fixed" : "absolute", bottom: mainobj.controlattrs.offsety, right: mainobj.controlattrs.offsetx, opacity: 0, cursor: "pointer" }).attr({ title: "backtotop" }).click(function () { mainobj.scrollup(); return false }).appendTo("body"); if (document.all && !window.XMLHttpRequest && mainobj.$control.text() != "") { mainobj.$control.css({ width: mainobj.$control.width() }) } mainobj.togglecontrol(); $('a[href="' + mainobj.anchorkeyword + '"]').click(function () { mainobj.scrollup(); return false }); $(window).bind("scroll resize", function (e) { mainobj.togglecontrol() }) }) } }; scrolltotop.init();