JS控制图片等比例缩放的代码

用js实现图片等比例缩放，一例（js等比例缩放图片 http://www.jbxue.com/article/19127.html）的代码。
1，js代码部分
<SCRIPT language="JavaScript">  
function DrawImage(ImgD,FitWidth,FitHeight){    
    var image=new Image();    
    image.src=ImgD.src;    
    if(image.width>0 && image.height>0){    
        if(image.width/image.height>= FitWidth/FitHeight){    
            if(image.width>FitWidth){    
                ImgD.width=FitWidth;    
                ImgD.height=(image.height*FitWidth)/image.width;    
            }    
            else{    
                ImgD.width=image.width;    
                ImgD.height=image.height;    
            }    
        }    
        else{    
            if(image.height>FitHeight){    
                ImgD.height=FitHeight;    
                ImgD.width=(image.width*FitHeight)/image.height;    
            }    
            else{    
                ImgD.width=image.width;    
                ImgD.height=image.height;    
            }    
        }    
    }    
}    
  
</script>

调用方法：
<a href="admin/<? echo $rscase['path']?>" target="_blank"><img src="admin/<? echo $rscase['path']?>" alt="点击放大图片" width="180" height="180" onload='javascript:DrawImage(this,180,);' hspace="3" vspace="3" border="0" /></a>