function changeImg(obj,width,height) {
          var scale,comp,w=obj.width,h=obj.height;
          if ( w > width || h > height ) {
            var scale1 = w / width;
            var scale2 = h / height;
            if(scale1 > scale2){scale = scale1;comp=obj.wi}else{scale = scale2;}
            w=Math.round(w / scale);h=Math.round(h / scale);
            obj.width = w;obj.height = h;
          }
          obj.style.padding=(height-h)/2+"px "+(width-w)/2+"px";
        }