function DownImage(ImgD){   //jsͼƬ¸ßËõ·Å´úÂë
    var image=new Image(); 
    image.src=ImgD.src; 
    if(image.width>0 && image.height>0){ 
        //flag=true; 
        if(image.height>=52){ 
            ImgD.height=52; 
            ImgD.width=(image.width*52)/image.height; 
        }else{ 
            ImgD.width=image.width; 
            ImgD.height=image.height; 
        }  
    } 
}