关键在于：max-width:780px;以及下面那行。
固定像素适应:
以下是引用片段：
<style type="text/css">
<!--
body {
font-size: 12px;
text-align: center;
margin: 0px;
padding: 0px;
}
#pic{
margin:0 auto;
width:800px;
padding:0;
border:1px solid #333;
}
#pic img{
max-width:780px;
width:expression(document.body.clientWidth > 780? "780px": "auto" );
border:1px dashed #000;
}
-->
</style>
</head>
<body>
<div id="pic">
<img src="/articleimg/2006/03/3297/koreaad_10020.jpg"/>
</div>
</body>
</html>
百分比适应:
以下是引用片段：
<style type="text/css">
<!--
body {
font-size: 12px;
text-align: center;
margin: 0px;
padding: 0px;
}
#pic{
margin:0 auto;
width:800px;
padding:0;
border:1px solid #333;
}
#pic img{
max-width:780px;
width:expression(document.body.clientWidth>document.getElementById("pic").scrollWidth*9/10? "780px": "auto" );
border:1px dashed #000;
}
-->
</style>
</head>
<body>
<div id="pic">
<img src="/articleimg/2006/03/3297/koreaad_10020.jpg"/>
</div>
</body>
</html>