                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /信息滾動效果制作

自己寫了一下html/css,但加上js后執行不了，希望大家幫忙看看

<!DOCTYPE?HTML>
<html>
<head>
<title>滾動欄</title>
<style?type="text/css">
*{margin:0;
??padding:0;}
a:link{color:black;text-decoration:none;}
a:visited{color:black;text-decoration:none;}
a:hover{color:red;text-decoration:none;}
.imooc{height:px;
???????width:400px;
???????margin:0?auto;
???????border:2px?solid?black;
	???border-radius:?15px;
	???position:relative;
	???top:50px;
}
.imooc?.new{background:#f05e6f;
			height:70px;
			border-top-left-radius:15px;
			border-top-right-radius:15px;
			color:#fff;
}
.imooc?.new?h1{padding:5px?0?0?8px;;

}
.imooc?.new?p{float:right;
			???margin-bottom:10px;
}
.imooc?.newclass?ul{list-style:none;
				?font-size:12px;
}
.imooc?.newclass?ul?li{padding:5px?0?5px?20px;

}				
.imooc?.newclass?ul?span{float:right;
					???padding-right:30px;
					???color:#ababab;

}
</style>
</head>
<body>
<div?class="imooc">
	<div?class="new">
		<h1>最新課程</h1>
		<p>更多>></p>
	</div>
	<div?class="newclass">
		<ul?id="con1">
			?<li><a?href="#">1.學會html5?絕對的屌絲逆襲（案例）</a><span>2013-09-18</span></li>
?????????????<li><a?href="#">2.tab頁面切換效果（案例）</a><span>2013-10-09</span></li>
			?<li><a?href="#">3.圓角水晶按鈕制作（案例）</a><span>2013-10-21</span></li>
?????????????<li><a?href="#">4.HTML+CSS基礎課程(系列)</a><span>2013-11-01</span></li>
?????????????<li><a?href="#">5.分頁頁碼制作（案例）</a><span>2013-11-06</span></li>
?????????????<li><a?href="#">6.導航條菜單的制作（案例）</a><span>2013-11-08</span></li>
?????????????<li><a?href="#">7.信息列表制作(案例)</a><span>2013-11-15</span></li>
?????????????<li><a?href="#">8.下拉菜單制作(案例)</a><span>2013-11-22</span></li>
?????????????<li><a?href="#">9.如何實現“新手引導”效果</a><span>2013-12-06</span></li>
		</ul>
		<ul?id="con2">
		</ul>
	</div>
</div>
<script?type="text/javascript">
?var?area?=?document.getElementById('newclass');
?var?con1?=?document.getElementById('con1');
?var?con2?=?document.getElementById('con2');
?var?speed?=?50;
?area.scrollTop?=?0;
?con2.innerHTML?=?con1.innerHTML;
?function?scrollUp(){
	?if(area.scrollTop?>=?con1.scrollHeight)?{
		?area.scrollTop?=?10;
		?}else{
		???area.scrollTop?++;?
		?}?
}
var?myScroll?=?setInterval("scrollUp()",speed);
area.onmouseover?=?function(){
	?clearInterval(myScroll);
	}
area.onmouseout?=?function(){
	?myScroll?=?setInterval("scrollUp()",speed);
	}
?</script>
</body>
</html>

谷歌瀏覽器報錯為：Cannot set property 'scrollTop' of null

可能是我的css代碼有問題，但個人能力有限，希望大家幫我看下