var myAlert = document.getElementById("alert");
var reg = document.getElementById("login").getElementsByTagName("a")[0];
var mClose = document.getElementById("close");
reg.onclick = function()
{
  myAlert.style.display = "block";
  myAlert.style.position = "absolute";
  myAlert.style.top = "25%";
  myAlert.style.left = "50%";
  myAlert.style.marginTop = "-75px";
  myAlert.style.marginLeft = "-150px";
  mybg = document.createElement("div");
  mybg.setAttribute("id","mybg");
  mybg.style.background = "#000000";
  mybg.style.width = "100%";
  mybg.style.height = "100%";
  mybg.style.position = "absolute";
  mybg.style.top = "0";
  mybg.style.left = "0";
  mybg.style.zIndex = "500";
  mybg.style.opacity = "0.3";
  mybg.style.filter = "Alpha(opacity=30)";
  document.body.appendChild(mybg);
  //document.body.style.overflow = "hidden";
}
mClose.onclick = function()
{
 myAlert.style.display = "none";
 mybg.style.display = "none";
}