图片放大查看效果

<script language="JavaScript">
<!--
var smallX = 200; //缩略图宽度
var bigX = 600; //预览窗大小,可以任意设置
var bigY = 450;
var srcX = -1; //原图大小,可以任意设置. 如都为-1将使用图片原始大小
var srcY = -1;
var border = 5; //边框
var smallY,viewX,viewY,bl,isIE,vX,vY;
window.onload=function (){
	head.innerHTML="图片已载入";
	isIE=window.event?1:0;
	if (srcX==-1 && srcY==-1){srcX=bigpic.width;srcY=bigpic.height;}
	else{bigpic.width=srcX;bigpic.height=srcY;}
	smallY=srcY*smallX/srcX;
	viewX=bigX/srcX*smallX; //预览范围
	viewY=bigY/srcY*smallY;
	bl=srcX/smallX; //缩小比例
	smallpic.width=smallX;
	smallpic.height=smallY;
	smallbox.style.borderWidth=border;
	smallbox.style.width=smallpic.offsetWidth+border*2*isIE;
	smallbox.style.height=smallpic.offsetHeight+border*2*isIE;
	bigbox.style.borderWidth=border;
	bigbox.style.width=bigX+border*2*isIE;
	bigbox.style.height=bigY+border*2*isIE;
	view.style.left=smallbox.offsetLeft + border;
	view.style.top=smallbox.offsetTop + border;
	view.style.width=viewX- !isIE*3+1;
	view.style.height=viewY- !isIE*3+1;
}
function move(e){
	var e = window.event?window.event:e;
	if (!isIE){vX=e.pageX-border-smallbox.offsetLeft;
	vY=e.pageY-border-smallbox.offsetTop}
	else{vX=e.offsetX;vY=e.offsetY}
	vX+=-viewX/2;
	vY+=-viewY/2;
	if (vX < 0) vX = 0;
	if (vY < 0) vY = 0;
	if (vX > smallX - viewX) vX = smallX - viewX;
	if (vY > smallY - viewY) vY = smallY - viewY;
	bigpico.style.marginLeft = - vX * bl;
	bigpico.style.marginTop = - vY * bl;
	view.style.left = vX + smallbox.offsetLeft + border;
	view.style.top = vY + smallbox.offsetTop + border;
}
//-->
</script>
<style type="text/css">
<!--
*{padding:0;margin:0}
body{background:black}
img{display:block;}
#smallbox{border:1px #c33 solid;float:left;width:0;height:0;overflow:hidden;font-size:0px}
#bigbox{border:1px #c33 solid;width:0px;height:0px;float:left;overflow:hidden;font-size:0px}
#view{border:1px #ddd solid;width:0px;height:0px;position:absolute;font-size:0px}
#head{text-align:center;line-height:40px;font:bold 16px/40px;color:pink}
//-->
</style>
<div id="head">图片loading...</div>
<div id="smallbox"><img id="smallpic" src="http://images2.wowchina.com/images_wow/download/wallpapers/2007/11/7/55591.jpg" border="0" onmousemove="move(event)"></div>
<div id="bigbox"><div id="bigpico"><img id="bigpic" src="http://images2.wowchina.com/images_wow/download/wallpapers/2007/11/7/55591.jpg" border="0"></div></div>
<div id="view" onmousemove="if (!isIE) move(event)"></div>