function DownImage(ImgD,MaxWidth,MaxHeight,alignX,alignY)
{
    alignX=alignX||1;
    alignY=alignY||1;
    var image=new Image();
    image.src=ImgD.src;
    if(image.width>0 && image.height>0)
    {
	    var rate = (MaxWidth/image.width < MaxHeight/image.height)?MaxWidth/image.width:MaxHeight/image.height;
	    var wid=0;
	    var hid=0;
	    if(rate <= 1)
	    {
		    wid=ImgD.width=image.width*rate;
		    hid=ImgD.height=image.height*rate;
	    }
	    else
	    {
		    wid=ImgD.width=image.width;
		    hid=ImgD.height=image.height;
	    }
	    if(alignX==1)
	    {
		    var ii=(MaxWidth-wid)/2;
		    ImgD.style.marginLeft=ImgD.style.marginRight=ii+"px";
	    }
	    if(alignY==1)
	    {
		    var ii=(MaxHeight-hid)/2;
		    ImgD.style.marginTop=ImgD.style.marginBottom=ii+"px";
	    }
    }
}