function getridof () {
mydiv = document.getElementById("coverlay");
mydiv.style.display = "none"; //to hide it
mydiv = document.getElementById("alerter");
mydiv.style.display = "none"; //to hide it
}

function popup (alerterheader, alertertext) {
mydiv = document.getElementById("coverlay");
mydiv.style.display = "block";
mydiv = document.getElementById("alerter");
mydiv.style.display = "block";
document.getElementById("alerttext").innerHTML = alertertext;
document.getElementById("alertheader").innerHTML = alerterheader;
}