var top = jquery("#div_id").offset().top; //获取div的居上位置
var left = jquery("#div_id").offset().left; //获取div的居左位置
var height = jquery("#div_id").height(); //获取div的高度
var width = jquery("#div_id").width(); //获取div的宽度
jquery("#div_id").css({'top':top,'left':left,'height':height,'width':width}); //设置DIV的css属性

<a href="http://localhost/#" rel="external nofollow" onclick="javascript:get_a(this,1)">获取A标签的位置</a>
<script language="javascript">
function get_a(thisObj,param){
 var top = jquery(thisObj).offset().top;
 var left = jquery(thisObj).offset().left;
 var height = jquery(thisObj).height();
 var width = jquery(thisObj).width();
}
</script>