function DownImage(ImgD){ 
   var image=new Image();
   image.src=ImgD.src;
   if(image.width>0 && image.height>0){
    flag=true;
    if(image.width/image.height>=170/180){
     if(image.width>170){  
     ImgD.width=170;
     ImgD.height=(image.height*170)/image.width;
     }else{
     ImgD.width=image.width;  
     ImgD.height=image.height;
     }

     }
    else{
     if(image.height>180){  
     ImgD.height=180;
     ImgD.width=(image.width*180)/image.height;     
     }else{
     ImgD.width=image.width;  
     ImgD.height=image.height;
     }

     }
    }

   }