操作滤镜的方法

//IE

obj.filters.alpha.opacity+=1;

 

//firefox

var al=parseFloat(obj.style.opacity);
al += 0.01;
obj.style.opacity = al;

 

 

//一个调整滤镜透明度的函数

function showBackground(obj,endInt)
{
    if(isIe)
   {
       obj.filters.alpha.opacity+=1;
       if(obj.filters.alpha.opacity<endInt)
       {
           setTimeout(function(){showBackground(obj,endInt)},5);
       }
   }else{
        var al=parseFloat(obj.style.opacity);
        al += 0.01;
        obj.style.opacity = al;
        if(al<(endInt/100))
        {
             setTimeout(function(){showBackground(obj,endInt)},5);
        }

    }

}