var elementa = document.getElementById('black');
var element = document.getElementById('mailing');
var duration = 1000;  /* 1000 millisecond fade = 1 sec */
var steps = 20;       /* number of opacity intervals   */
var delay = 99999999;     /* 5 sec delay before fading out */

/* set the opacity of the element (between 0.0 and 1.0) */
function setOpacity(level) {
element.style.opacity = level;
elementa.style.opacity = level;
element.style.MozOpacity = level;
elementa.style.MozOpacity = level;
element.style.KhtmlOpacity = level;
elementa.style.KhtmlOpacity = level;
element.style.filter = "alpha(opacity=" + (level * 100) + ");";
elementa.style.filter = "alpha(opacity=" + (level * 100) + ");";
}

function fadeIn(){
for (i = 0; i <= 1; i += (1 / steps)) {
  setTimeout("setOpacity(" + i + ")", i * duration);
}

}
setTimeout("fadeIn()",500);