xhtml 下 overflow:hidden 失效了?解决方案 _HTML/CSS

xhtml 下 overflow:hidden 失效了?

HTML code


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>图片循环</title>
</head>

<body>
<DIV align=center>
            <DIV style="overflow:hidden;width:210px; border:1px solid #000;" >
                                <DIV id=news  style="width:100px;LEFT: 0px; WHITE-SPACE: nowrap; POSITION: relative; TOP: 0px;border:1px solid #000; z-index:1"><SPAN id=nbo><IMG height=80 
                                src="images/1_1.jpg" width=80> <IMG 
                                height=80 src="images/2_1.jpg" 
                                width=80> <IMG height=80 
                                src="images/3_1.jpg" width=80> <IMG 
                                height=80 src="images/4_1.jpg" 
                                width=80> <IMG height=80 
                                src="images/1_1.jpg" width=80> <IMG 
                                height=80 src="images/2_1.jpg" 
                                width=80> <IMG height=80 
                                src="images/3_1.jpg" width=80> <IMG 
                                height=80 src="images/4_1.jpg" 
                                width=80></SPAN>
                                <SCRIPT language=javascript>
//重复一次新闻内容
document.write(nbo.innerHTML);
</SCRIPT>
                                 </DIV></DIV>
                                <SCRIPT language=javascript>
//实现不间断滚动
function newsScroll()
{
  news.style.pixelLeft=(news.style.pixelLeft-1)%nbo.offsetWidth;
}
//timer1=setInterval('newsScroll()',20)  //更改第二个参数可以改变速度，值越小，速度越快。
</SCRIPT>
                      </DIV>

</body>
</html>

这段代码中把 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 去掉或换成 html就正常

请高手解决!

------解决方案--------------------
<DIV style="overflow:hidden;width:210px; border:1px solid #000;" >
+ "position:relative;"