用JavaScript在网页右下角弹出窗口

该代码在IE和FF下测试通过：

代码

<html>
<head>
<script language="JavaScript" type="text/javascript">
            function $(obj){
                return document.getElementById(obj);
            }
            function pop(obj){
                var h = parseInt(currentStyle($("popDiv")).height);
                $("popDiv").style.height = (h + obj) + "px";
                if(parseInt($("popDiv").style.height) < 2){
                    window.clearInterval(timer);
                    $("popDiv").style.display = "none";
                }
                if(parseInt($("popDiv").style.height) >= 200){
                    window.clearInterval(timer);
                }

            }
            function currentStyle(element) {
               return element.currentStyle || document.defaultView.getComputedStyle(element, null);
            }


            var timer;
            function runtimer(obj){
                timer = window.setInterval(function(){pop(obj)},10);
            }
            window.onload = function(){
                runtimer(2);
            }
</script>

</head>

<body >
<div style="position:absolute;right:0;bottom:0;height:0px;200px;border:1px solid red;" id="popDiv">
        <a href="javascript:runtimer(-2);">×</a>
        </div>

</body>
</html>

注意:在IE下获取控件的当前css要用currentStyle，而不能用style(该属性获取元素内嵌的样式，在该例子中明显不合适)，而在FF下要通过document.defaultView.getComputedStyle(element, null);获得当前css.