刚才解答论坛上一个帖子顺手写的代码，贴出来免得下次找不着。
<html><head><title>emu</title></head><body><BR>原图：<BR><img src="http://img.pconline.com.cn/images/photo2/839980/1118509777696.JPG" onmousemove="zoom()" id=srcImg><BR>局部放大图：<BR><div style="overflow:hidden"><img id=zoomImg></div><SCRIPT LANGUAGE="JavaScript"><!--zoomImg.src = srcImg.src;srcImg.height = srcImg.height/2;var zoomRate = 5;zoomImg.height = srcImg.height*zoomRate;zoomImg.parentNode.style.width = srcImg.width;zoomImg.parentNode.style.height = srcImg.height;function zoom(){var elm = event.srcElement;h = elm.offsetHeight/zoomRate/2;w = elm.offsetWidth/zoomRate/2;var x = event.x-elm.offsetLeft;x=x<(elm.offsetWidth-w)?x<w?w:x:elm.offsetWidth-w;zoomImg.style.marginLeft=(w-x)*zoomRate;var y = event.y-elm.offsetTop;y=y<(elm.offsetHeight-h)?y<h?h:y:elm.offsetHeight-h;zoomImg.style.marginTop=(h-y)*zoomRate;}//--></SCRIPT></body></html>
|