图片的明暗变化

下面为效果显示

脚本说明:
把如下代码加入<body>区域中：
<script>
function hover(id,opacity){
       document.all[id].filters.alpha.opacity = opacity;
}

function opacify(id,delay,start,stop){
    opacify(id,delay,start,stop,0);
    }
    
function opacify(id,delay,start,stop,offset){
    offset *= 1000;
    if (document.all){
        hover(id,start);
        setTimeout("fadeOut('"+id +"',"+ delay +","+ start +","+stop +")",offset);
        }
    }

function fadeOut(id,delay,start,stop){
    if (document.all[id].filters.alpha.opacity > stop){
        document.all[id].filters.alpha.opacity -= 2;
        setTimeout("fadeOut('"+ id +"',"+ delay +","+ start +","+ stop +")",delay);
        }
    else {
        setTimeout("fadeIn('"+ id +"',"+ delay +","+ start +","+ stop +")",delay);
        }
    }   
    
function fadeIn(id,delay,start,stop){
    if (document.all[id].filters.alpha.opacity < start){
        document.all[id].filters.alpha.opacity += 2;
        setTimeout("fadeIn('"+ id +"',"+ delay +","+ start +","+ stop +")",delay);
        }
    else {
        setTimeout("fadeOut('"+ id +"',"+ delay +","+ start +","+ stop +")",delay);
        }
    }

</script>
<img src="anarchos_button.jpg" name="imageName" onLoad="opacify('imageName',22,100,20)" style="filter:alpha(opacity=100);" alt="blah" />