#ackalert {
    border: 1px solid black;
    width: 400px;
    min-height: 300px;
    display: block;
    padding: 5px;
    text-align: center;
    z-index: 2;
    position: absolute;
    left: 200px;
    top: 200px;
    background-color: #f0f0f0;
}
#ackback {
    z-index: 1;
    opacity: 0.5;
    background-color: #040;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}
.abtn {
    display: inline;
    border: 1px solid black;
    width: 80px;
    background: #a0a0a0;
    padding: 5px 8px;
    margin: 5px 0;
    text-align: center;
    border-radius: 2px;
    color: white;
    text-decoration: none;
}