js代码:
$.fn.smartFloat = function() { var position = function(element) { var top = element.position().top, pos = element.css("position"); element.css({ position: "fixed", right:"10px",bottom:"10px" }); $(window).scroll(function() { var scrolls = $(this).scrollTop(); element.css({ position: "fixed", right:"10px",bottom:"10px" }); }); }; return $(this).each(function() { position($(this)); }); }; $(function(){ $("#messagePlace").smartFloat(); });效果图: