var op = 0;

function fade()
{
if(op==0)
    fadeIN();
else
    fadeOUT();

}


function fadeIN(){
_v = document.getElementById('popup');

op += 5;

if(op < 100)
    {
    if(window.sidebar)
            _v.style.opacity = op/100;
        else
            //_v.filters[0].Opacity = op;
            _v.style.filter ="progid:DXImageTransform.Microsoft.Alpha(Opacity=" + op + ")";
     setTimeout("fadeIN()",10);
     

     }
else
    {
    op=100;
 
    }
}

function fadeOUT(){
_v = document.getElementById('popup');

op -= 5;

if(op > 0)
    {
    if(window.sidebar)
            _v.style.opacity = op/100;
        else
            //_v.filters[0].Opacity = op;
            _v.style.filter ="progid:DXImageTransform.Microsoft.Alpha(Opacity=" + op + ")";
     setTimeout("fadeOUT()",10);
     

     }
else
    {
    op=0;
 
    }
}