function imageResize(ImgD,proMaxWidth,proMaxHeight){
    var image=new Image();
    image.src=ImgD.src;
    if(image.width>0 && image.height>0){
      var rate = (proMaxWidth/image.width < proMaxHeight/image.height)?proMaxWidth/image.width:proMaxHeight/image.height;
      if(rate <= 1){   
        ImgD.width = image.width*rate;
        ImgD.height =image.height*rate;
      }else {
        ImgD.width = image.width;
        ImgD.height =image.height;
      }
    }
}