function DrawImage(ImgD,width,height){
        var image=new Image();
        var iwidth =100; //定义允许图片宽度，当宽度大于这个值时等比例缩小
        var iheight = 100; //定义允许图片高度，当宽度大于这个值时等比例缩小
        if(width!=undefined)
        {
            iwidth=width;
        }
        if(iheight != undefined)
        {
            iheight =height;
        }
        try
        {
            image.src=ImgD.src;
            if(image.width>0 && image.height>0)
            {
                ImgD.width=51; //显示最小值
                ImgD.height=51;

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

                   // ImgD.alt=image.width+"×"+image.height;
                }
                else
                {
                    if(image.height>iheight)
                    { 
                       ImgD.height=iheight;
                        ImgD.width=(image.width*iheight)/image.height; 
                    }
                    else
                    {
                       ImgD.width=image.width; 
                       ImgD.height=image.height;
                    }
                  // ImgD.alt=image.width+"×"+image.height;
                }
             }
        }
        catch(E)
        {
            ImgD.width =iwidth;
            ImgD.height =iheight;
        }
}