var flag=false;
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;
      }
    }
    else
    {
      if(image.height>iheight)
      { 
        ImgD.height=iheight;
        ImgD.width=(image.width*iheight)/image.height; 
      }
      else
      {
        ImgD.width=image.width; 
        ImgD.height=image.height;
      }
    }
  }
} 
//<Img src="imageUrl" onload="javascrip:DrawImage(this,100,100)">