interval = '';
function changeOpac(opacity, id) {
    object = document.getElementById( id ).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}
function fade(id, start, stop, duration, steps )
{
    changeOpac(0, id);
    for( var i = 0; i < steps; i++ )
    {
        window.setTimeout( 'changeOpac( '+Math.abs(start-stop)/steps*i+', "'+id+'" )', ( duration / steps * i )+500 );
    }
}