function opacity(id, opacStart, opacEnd, millisec) {

    var speed = Math.round(millisec / 100);
    var timer = 0;

    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
}

function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
} 

function closeBox(id)
{
	opacity('alpha_bg',85,0,1500);
	opacity(id,85,0,150);
	
	document.cookie = 'box_newsletter=1;'
	document.getElementById(id).style.display = "none";
	document.getElementById('alpha_bg').style.display = "none";
}