织梦DedeCms v5.6/5.7 新图集页面怎么增加图片下载功能

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); 
};