织梦怎么为新图集页面增加图片下载功能

if(sina.isIE){   
this.ImgObj1.src = 'http://i0.sinaimg.cn/dy/deco/2008/0331/yocc080331img/news_mj_005.gif';   
  
this.ImgObj1.filters[0].Apply();   
  
this.ImgObj1.src = this.filmstrips[num].src;   
this.ImgObj1.filters[0].Play();   
}else{   
this.ImgObj1.src = this.filmstrips[num].src;   
for(i = 0;i <= 3;i ++){   
this._timeOut[i] = setTimeout("epidiascope.ImgObj1.style.opacity = " + i * 0.3,i * 100);   
};   
this._timeOut[i] = setTimeout("epidiascope.ImgObj1.style.opacity = 1;",4 * 100);   
};