/*按比例生成缩略图*/
function DrawImage(MyPic,W,H){
  var flag=false;
  var image=new Image();
  image.src=MyPic.src;
  if(image.width>0 && image.height>0){
    flag=true;
    if(image.width/image.height>= W/H){
      if(image.width>W){  
        MyPic.width=W;
        MyPic.height=(image.height*W)/image.width;
      }
	  else{
        MyPic.width=image.width;  
        MyPic.height=image.height;
      }
    }
    else{
      if(image.height>H){  
        MyPic.height=H;
        MyPic.width=(image.width*H)/image.height;     
      }
	  else{
        MyPic.width=image.width;  
        MyPic.height=image.height;
      }
    }
  }
} 

//无级缩放图片大小
function bbimg(o)
{
  var zoom=parseInt(o.style.zoom, 10)||100;
  zoom+=event.wheelDelta/12;
  if (zoom>0) o.style.zoom=zoom+'%';
  return false;
}
//改变图片大小
function resizepic(thispic)
{
if(thispic.width>600) thispic.width=600;
}