示例代碼例1：

<script?type="text/javascript"?src="http://code.jquery.com/jquery-latest.js"></script>???

<script>???

$(function()?{???

var?elm?=?$('#pordAttr');???

var?startPos?=?$(elm).offset().top;???

$.event.add(window,"scroll",?function()?{???

var?p?=?$(window).scrollTop();???

$(elm).css('position',((p)?>?startPos)???'fixed'?:?'static');???

$(elm).css('top',((p)?>?startPos)???'0px'?:?'');???

????});???

});???

</script>??

示例代碼例2：

$(function(){??

//獲取要定位元素距離瀏覽器頂部的距離??

var?navH?=?$(".nav").offset().top;??

//滾動條事件??

$(window).scroll(function(){??

//獲取滾動條的滑動距離??

var?scroH?=?$(this).scrollTop();??

//滾動條的滑動距離大于等于定位元素距離瀏覽器頂部的距離，就固定，反之就不固定??

if(scroH>=navH){??

$(".nav").css({"position":"fixed","top":0});??

}else?if(scroH<navH){??

$(".nav").css({"position":"static"});??

}??

})??

})??