                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /DOM事件探秘

JS部分onmousedown不起作用，大家幫忙看看

<!DOCTYPE?html>
<html>
	<head>
		<meta?charset="UTF-8">
		<title></title>
		<style?type="text/css">
		#box{
			width:?400px;
			height:?250px;
			background-color:?#F0FFFF;
			border:?solid?cornflowerblue;
			top:?200px;
			left:?300px;
			position:?absolute;
		}
		#login{
			width:?400px;
			height:?30px;
			border-bottom:?solid?cornflowerblue;
			background-color:?cornflowerblue;
			margin-top:-18px;
		}
		#login?p{
			text-align:?center;
			color:#F0FFFF;
			font-weight:900;
			font-size:?large;
			
		}
		</style>
		<script?type="text/javascript">
			
			window.onload=drag;
			function?drag(){
				var?login=document.getElementById("login").childNodes[0];
				login.onmousedown=fndown();
			}
			function?fndown(){
				document.onmousemove=function(event){
					var?box=document.getElementById("box");
					box.style.left=event.clientX+'px';
					box.style.top=event.clientY+'px';
				}
			}
		</script>
		
	</head>
	<body>
		<div?id="box">
			<div?id="login"><p>登錄</p></div>
		</div>
	</body>
</html>

就是鼠標不用按下去，窗口都會跟著鼠標走