function shrink(ImgObj,FitWidth,FitHeight){
     var image = new Image();
     image.src = ImgObj.src;
     if(image.width > 0 && image.height > 0){
         if(image.width / image.height >= FitWidth/FitHeight){
             if(image.width > FitWidth){
                 ImgObj.width = FitWidth;
                 ImgObj.height = (image.height*FitWidth) / image.width;
             }else{
                 ImgObj.width = image.width; 
                 ImgObj.height = image.height;
             }
         } else{
             if(image.height > FitHeight){
                 ImgObj.height = FitHeight;
                 ImgObj.width = (image.width*FitHeight) / image.height;
             }else{
                 ImgObj.width = image.width; 
                 ImgObj.height = image.height;
             } 
        }
     }
 }