//图片按比例缩放
var flag=false;
//调用：<img src="图片" onload="Javascript:DrawImage(this)">
function DrawImage(ImgD,iwidth,iheight)
{
  var image=new Image(); 
  image.src=ImgD.src;
  if(image.width>0 && image.height>0)
  {
   flag=true;    
   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;
    }
     
  }
  //alert(ImgD.style.display);
  ImgD.style.display="block";
}