图片javascript缩小

function SetSize(obj, width, height)
{
myImage = new Image();
myImage.src = obj.src;
if (myImage.width>0 && myImage.height>0)
{
var rate = 1;
if (myImage.width>width || myImage.height>height)
{
if (width/myImage.width<height/myImage.height)
{
rate = width/myImage.width;
}
else
{
rate = height/myImage.height;
}
}
if (window.navigator.appName == "Microsoft Internet Explorer")
{
obj.style.zoom = rate;
}
else
{
obj.width = myImage.width*rate;
obj.height = myImage.height*rate;
}
}
} 

用法： 

<img src="img/offer/41936519.jpg" border="0" style="zoom: 0.1" onload="SetSize(this, 80, 60)"/>