javascript代碼控制圖片在頁面顯示時等比例縮放

 <script language="javascript" type="text/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>

調用時：<img src="1.jpg"  border="0" οnlοad="javascript:DrawImage(this,500,500);"/>