等比例縮圖
建立一圖片，設定OnLoad事件
<img src="xxx.jpg" onload="DrawImage(this.value,150,150)">
--- JS Code ---
function DrawImage(ImgD,w,h){ var image=new Image(); image.src=ImgD.src; 
if(image.width>0 && image.height>0){ 
if(image.width>0 && image.height>0)
flag=true; 
if(image.width/image.height>= w/h){ 
if(image.width/image.height>= w/h)if(image.width>w){ ImgD.width=w; ImgD.height=(image.height*w)/image.width; }else{ ImgD.width=image.width; ImgD.height=image.height; 
} //ImgD.alt=image.width+"×"+image.height; } else{ if(image.height>h){ ImgD.height=h; ImgD.width=(image.width*h)/image.height; }else{ ImgD.width=image.width; ImgD.height=image.height; 
}