js自动生成缩略图

放入head里面

<script language="javascript">
<!--
var flag=false;
function DrawImage(ImgD){
var image=new Image();
image.src=ImgD.src;
if(image.width>0 && image.height>0){
flag=true;
if(image.width/image.height>= 164/112){
if(image.width>164){
ImgD.width=164;
ImgD.height=(image.height*164)/image.width;
}else{
ImgD.width=image.width;
ImgD.height=image.height;
}
ImgD.alt=image.width+"×"+image.height;
}
else{
if(image.height>112){
ImgD.height=112;
ImgD.width=(image.width*112)/image.height;
}else{
ImgD.width=image.width;
ImgD.height=image.height;
}
ImgD.alt=image.width+"×"+image.height;
}
}
}
//-->
</script>

图片调用
程序代码：
<a href="<%=trim(rs("picurl"))%>" target="_blank"><img src="<%=trim(rs("imgurl"))%>" border="0" width="164" height="112" onload="javascript：DrawImage(this);"></a>